Kraftwerker

Gary, I've no clue. ? Internet sleuths could probably find it.

Gary, Thanks for the recognition. There were two things in play with John's product. Subterfuge. The ACME resin body distribution was off the record. John intended to sell his kits mainstream. So, we did not want to thumb our nose at the original Japanese product maker. Even though it was extremely doubtful they could have sold more product outside of Japan (huge price and language hurdles). So, John made some things "different" to say it was not an outright copy. Normalizing. That bump is like a typical engine access panel. The baseline 500A design required flipping the headrest up and then flipping the whole rear bodywork back to get to the engine. Some owner had another opening added to give ease of access. This is very unique. As stated in the posts above, the "normal" 550A did not have such. To make his subject more appealing, John eliminated the bump/access.

I can add some history to this. The ACME 550A was a bootleg product. Long ago, (before internet) it was very difficult to acquire garage production resin kits from overseas. Japanese transactions were difficult due to language of course, and the prices were extraordinary, by ANY measure. Mike Q. and I made reproductions of resin bodies sourced from Japan. These were made available to a small circle of enthusiasts. The baseline subject 550A was indeed unique (rear deck bump) to a car in Japan. The Flintstone product can be traced to ACME origins. Similarly, John Johnson (Teapot Graphics) developed his 550A kit from ACME origins.