Good luck on your relocation. My wife and I did much the same thing about 20 years ago moving from Sacramento to the Kansas City area. Many of the same issues, and I stayed behind for a few months to get the house sold. It took a couple of months to find the job I wanted, but it happened and we are both very happy that we moved. Much better over all quality of life. Again good luck to you and your family.
There is a program on MAVTV that has a one man shop that builds some unusual cars. They had a show last year where a client brought in a VW Bus to have him make a hot rod for him. He built a frame with an exposed front engine and a shortened body just like your drawing. I know yours has a rear VW engine. The guys on Gas Monkey did the shortened bus with the built rear VW engine. As I recall they were having a hard time trying to sell it at a profit. I enjoy following builds of this type. Beyond my skill set but I still learn a great deal from the builders.
As an additional thought. Look at the engine in the AMT '51 Chevy hardtop. It has a build option of a cross flow head with a magneto , nice headers, and fuel injection. The headers have six separate primary pipes into two. A very nice chrome valve cover. The kit also has some nice chrome traction bars and chrome wheels, two standard and two reversed. If you find one of the recent reissues of this kit it will have pad printed Racemaster slicks also.
What a shame to have more dollars than common sense. This new owner has a very large and expensive rebuild ahead of him. I remember seeing where someone was making reproduction bodies for this model Mustang. If he now has the title and depending on what state he intends to title it in this maybe the best way to go. Many states frown on moving the Vin. number from one car to another.
That looks just like the carb. they used to offer. The old version had a complete circular top so that an air cleaner could be mounted. Except for that it would look just like your picture. I think that a similar carb was used on both the 400 & 435 h.p. Corvettes and the Six Pack Dodge 440's in the mid to late 60's.
As far as 1/24th or 1/25th scale I would think that with some very careful cutting you could make two of these by splitting a Holly double pumper carb. in half and remove the "air horn" or choke assembly from the primary side. In 1:1 this would be a competition type carb. No choke assembly. Years ago Holly offered a two barrel carb much like this but with the materials of the day. What they offered, at least in the 60's, was the front half of their model 4170 double pumper four barrel carb. This was used in the entry level class of NASCAR usually in the Hobby Stock 6 cylinder class. I'm sure there was many other areas that used it also. As I recall it was in the 300 - 400 CFM flow rate.
All in the name of progress. Next they'll do like Kansas: Give some wealthy developer a couple million dollar tax credit so they can build something. Since the state is giving them all this monies so they can build something and keep the income they will need to increase your home owners tax to offset the lost revenue, and the developer will skip town before they have to pay back the state. The rich just keep getting richer, and we just have to keep paying for it.
I have not had an opportunity to look inside ,but spoke with some people at the model shop. I was told that there is an optional front suspension system to build a gasser . I would be more inclined to switch the frame from the wagon too the coupe and build it that way if I was wanting to building a gasser.
I'm in the rake camp. It will give this type of build a much more aggressive look. With oversized rear tires on models setting level they then look as though they have been lowered in the rear. It's an optical illusion.
Last summer my wife and I went to dinner at one of our favorite places in Lawrence Ks. This is a popular micro brewery/sandwich place near the KU campus. After parking our car we saw a college age couple walking with their arms around each other like they were never going to let go. They were both on the phone with the free hand. I asked my wife if she thought they may be talking to each other. It's a communication devise, they might want to communicate with the other person if they're really interested enough to be intertwined while walking down the street.
As I'm sure you already know you would have to fill the gap on the rear deck from the top removal. If you already have the Olds kit that should work for the top boot. I did a similar conversion once using the boot from an AMT "65 GTO kit. The interior dog legs for the top can be done with some Plastruct products.