This is the kit I worked on and stalled more than 10 years ago.
It's got the boxer from Fujimi's Koenig TR.
This is the original ESCI engine. Looks pathetic, and you can see why I didn't use it. (Tamiya and Monogram ones are also usable, too)
Dusty interior.
The seats are scratchbuilt, using plastic sheet and epoxy putty.
Left is the kit wheel, and the right is Fujimi's 365 GTB wheels.
Problem is the 512BB should have wider wheels on the rear, so I will have to extend the rim, or graft the spokes on another wheel.
Together with the Fujimi's Enthu Dino, which I showed a few months ago, these two projects definitely have to be resumed.