"Legacy" tooling. There is a lot of it out there. Many kits offered by Round 2/ AMT/MPC are older 60's and '70's era designs.
Generally speaking, if the tool for a given subject still exists, this will discourage other companies or even the same company from developing a new tool, since, if the tool is still in good shape, the old one can always be reissued. There are a few exceptions however, the '69 Charger being one of them, as Revell developed a "modern" tool for the '68-'69 Charger about 20 years ago or so.
MPC, AMT and Jo Han created "annual" kits back in the 1960's and 70's, from around 1961- 1980. The same basic tool would be used for the same generation of car (for instance, for Dodge Chargers - '68, '69 and '70 kits), and a new tool would be developed for the next generation (for instance, the '71-'74 Charger annuals). Each generation was updated yearly, so some years were offered only once as an annual kit. The annual kits were developed as more or less state-of-the-art in the year they were developed. Dealer Promotional models (promos) were also crated from these basic tools- these were curbside pre-built showroom stock cars in an assortment of factory colors that were sold or given away at car dealerships. Original annual kits and Promos are very desirable on the collector's market due to their sometimes-vast building options, box art, and most of the time, very accurate body shapes. Many of these tools had a much longer production life than the original designers ever intended (if they survived, see below), sometimes being reissued 40 or 50 years later. The recent releases, while being crude by today's design standards, still often have a strong nostalgia factor with long time builders.
Here's an example by model. MPC really made the most of their tooling back then, switching and borrowing parts of tools to be combined with other kits, using bodies on Funny Car and NASCAR chassis, etc.
1966 - with stock, drag, custom and NASCAR/USAC style racing options. Also, "spy" parts (machine guns, rockets, and interior "controls" were included. I suspect that some of the tool (chassis, some of the engine) was based on those from the AMT (really MPC) '65 Dodge Coronet kit.
1967 - with stock, drag "funny" (a stock body mounted on a stock chassis that was made to tilt at the rear bumper), custom, and NASCAR/USAC style racing options. The body, bumpers, and interior were updated for 1967.
Color Me Gone funny car: the '67 body was modified into an altered wheelbase form. A new funny car chassis (which probably was shared with other MPC kits, but I don't remember the specifics) was used. It was only issued once in the late '60's. I seem to remember that at some point, whomever had the MPC tooling back about 15-20 years ago floated the idea of reissuing this kit, but nothing ever came of it.
The '67 annual tool mostly survived all of this.
The 1967 was reissued in the early '70's as a street machine (sliver on the box) with new 5 spoke mags, and some new drag parts, and M/T slicks, while the custom, racing parts, and some stock parts (wheels) were deleted.
In the '80's, it was released (black on the box), molded in black, with new ('80's-style) modular wheels, fat rear tires and side pipes added, along with a supercharger set up for the big Hemi. The custom, racing and stock parts that were deleted last time did not return.
In the late 90's, it was released more or less in the same form as it was in the '80's, but in gray plastic and with a yellow built on the box.
Just a few years ago, it was released again, in a retro box that looked just like the early '70's release. The old M/T slicks from the '70's were added back, along with new 5-spoke mags that looks mostly like the ones from the early 70's release.
That's just the '66-'67 Chargers.
The '68-'70 tool's history was MUCH more complicated (the MPC 2nd gen Charger tool had one of the most active and convoluted histories in the history of model cars, thanks in no small part to the Dukes of Hazzard).
Here's a short (haha!) rundown of the 2nd gen MPC Charger tool: '68 Annual & Promo, '69 Annual and Promo, '68 and '69 Color Me Gone and Mr. Norm's funny cars, '70 Annual & Promo, #71 Bobby Isaac '70 Daytona stock car with stock chassis, #22 Dick Brooks '70 Daytona stock car with generic NASCAR chassis, '69 General Lee (which took a LOT of restoration, and even then it not done very well), '69 Charger 500, '69 Daytona factory stock, various General Lees again, Fast and Furious, and reissues of the Daytona and 500 in between those. Oh yeah- and one last parting shot, done as the "Country Charger" (basically a Lee kit molded in black with new decals and 5-spoke mags added in). Did I miss any?
The first (1979 issue) Lee kits had a racing interior (from one of the Daytona stock cars) with stock bucket seats and dash. Later issues had the stock interior added back, as it was found for the 500 and Daytona kits that were to follow.
The General Lee pictured at the top probably still has the old "500/Daytona" window. That was changed for the Daytona in 1970 or so, it was not corrected for the General Lee in '79. It was left that way, correct as it was for the 500 and Daytona variants created in the late 80's / early 90's. The rear window was finally fixed (although it was not as nice as the original annual) with the Fast & Furious release in the 2000's.
I started building these MPC General Lee kits when I was about 9. I had to have a General Lee back then, and bought a bunch more to build as street machines & race cars, as it was the only game in town for Chargers in scale back in the early 80's. With some extra parts and some imagination, I was able to do a lot with those kits. While they are basic, they still do come together reasonably well.
My biggest beefs with the MPC '69 Charger tool are:
1) the hood is a '70 or Daytona style hood, per the vent design. The correct hood was available in the old '68 and '69 annuals, and the first release of the 500 kit. I wish Round 2 would bring that old correct hood back.
2) the rear valence panel is terrible. It was part of the body mold to start. My guess is that MPC put cuts into it in '79 so that the rear bumper could be inserted easier, it's held together with an oversized (structural? ) license plate, it's terrible as you can see. Round 2 should just cut it free from the body mold and tool a new one.
3) For the '79 General Lee, they added in grille inserts from their '71-'72 Charger kit. The original '69 inserts were nothing to write home about however. Round 2 could always tool up new ones for this kit.
As the license for Dukes of Hazzard stuff is essentially a dead issue (maybe rightly so, I won't get into that here), they could do worse than to tool a new hood, rear valence and grille inserts, and try to make it a modern 3-in-1, with a cool box and decals.
I suggest you try to have some fun with that kit. Test paint on it, cut it up, do what you like. Make it something that it is not. You could always try to find a 500 grille and make it into a 500.