Hi, the 80's bike was develop in France by Boxer Bike with Claude Fior who devellop a lot of frame for GP500 with special fork:
.
The frame of the lamborghini was like this:
and the engine was from an GPZ900r for the first one, 1000RX for the last one.
The bike you show in the first post is in France for sell:
http://www.leboncoin.fr/vi/33952783.htm?ca=22_sBut note that the fork is not the original one (it comes form an ZX7R)
Boxer Bike had produce other bike with VF engine like this one
Feel free to ask other pictures
STEPH
LRT Online