’71–’73 A65 Export tank? I don’t think it’s the worst idea I’ve had. I tried to scale this accurately in Photoshop and I think this could work well.
This metal Bultaco Mercurio tank currently on Ebay would also be extremely cool to have, and I would assume easy to fit. But $335 (including shipping from Spain) is getting pretty expensive for what is basically a rolling pile of garbage.