Well my 2004 V11 LeMans arrived today. So I met the shipper, brought her home, then tried to figure out how to remove the damn seat! Eventually, with the help of the Internet and multiple searches, I located the keyed seat release on her throttle side. :-0
Rigged up the battery tender and hope to fire her up tomorrow.
The Bellagio uses a sort of hybrid Tonti frame, after a fashion. The other three frames are twin beam perimeter type using the engine as a stressed member. They're all steel and heavy as a very, very heavy thing but they are stiff and robust. Take a look at the parts diagrams and you can clearly see the differences.