What grit are you using to sand the primer? If you're seeing "scratches" in the pearl, it's more likely sanding scratches in the primer coat. You may need to sand out to a finer grit on the primer before you do the pearl. You will want to void sanding the pearl, as it will ruin the pearl effect. If you do sand it, you'll need to give it at least 1 or 2 more coats to bring the effect back.
I see what you're thinking, but there is a minor flaw in the example you use. The Promo C1500s actually do have a separate hood, and the inner fenders and the molded in hood details are present on them. The bodies were designed to be able to released as both a promo and as a full detail kit. Doing the same using the original '60 kits would be more work.
No, they are not the same. The 6 didn't get the V8 bellhousing pattern until the "Hi Torque" 6 came out, 62 in Chevy II/Nova, 63 for all others (some early '63 4x4 trucks continued to use the older engine, though). Doing a '60 El Camino and Wagon/Sedan Delivery would require a retool of the chassis as well as the body. They used a different gas tank than the Sedan/Coupe/Convertible, and there are other differences as well. The driveline and suspension parts could be used as is, though.
I might have to see if I can find one of those 1/25 Olivers. Finding any 1/25 scale tractor is hard enough, I'm more than willing to use die cast if I have to. The tow truck is somewhat stalled at the moment, other projects have taken priority. It is currently sitting in primer, and I have modified the bed so it sits better on the chassis.
Another thing that might be giving you problems with the scratches is the sanding technique used. You always want to sand in straight lines as much as possible (sometimes that's hard to do on some parts). When you go to the next grit, you should try to sand at a different angle from the prior grit, say 45 to 90 degrees from the direction you sanded. This will prevent making any scratches deeper, and will aid in removing them.
I would suggest stripping them and going with a stainless steel finish. That would be closer to what you would find on a 1:1 street truck. The mufflers on the tips are not actually glass packs, but rather they are SuperTrapp mufflers. They're more of a motorcycle item, particularly off road motorcycles. They did manufacture them for cars and trucks, though, in the late '80s/early ;90s, and they were somewhat popular as they not only were quiet, but could be tuned for performance very easily. They fell out of favor when mufflers like Flowmaster and Magnaflow came out, which were much cheaper.
The version on the kit have the optional end cap. On the 1:1 version, polished stainless or brushed stainless were options.
It's a rubber type coating, primarily for tool handles. It's essentially the same material that you see on plier handles. Comes in 2 types, a can that you simply dip the tool in, which is the original version of the product, and it now also comes in a spray can. It won't hurt the plastic in any way, but it will go on very thick, and dries to a somewhat glossy vinyl appearance. I really can't think of any good modelling applications for it, other than perhaps replacing/adding grips to modelling tools. You might also be able to use it in a mold to make flexible parts, though I'm not sure how well it would set up.
Common problem on that kit, especially the later issues. The windshield on that kit is not correct to the 1:1 on any of the issues of it, though. The top of the glass should actually sit 3 scale inches back from the edge of the cab roof, like this
You could make a filler strip to correct it out of styrene.
That not 100% accurate. You can bring over "gray market" vehicles, but you cannot license or register them for road use until the met US emissions and safety standards., plus pay the import taxes and other fees. This includes supplying a bill of sale, motor vehicle tax forms RUT-35 or RUT-50, vehicle transaction form VSD-190, US customs form7501 "entry summary", DOT form HS-7, US EPA form 3520-1. There are exceptions; 1, the importer or importer's agent submits documentation that the vehicle is in compliance with US emissions and safety standards; 2,A manufacturers Certificate of Origin has been issued showing the vehicle is in compliance with US EPA and DOT standards; or 3, the vehicle is 25 years old or older. This all from the Grey Market Vehicle Guidelines brochure for the State of Illinois.