Admire the workmanship & adaptive ingenuity but..........WHY??
If you want a custom crotch rocket I think you could find something a little better to start off with than a big cruiser frame & engine. ???
Maybe it's just me but I try to think logically & some things I just don't get.
I have an aquaintance that has dumped well over $12K into hopping up his Harley bagger. It runs like a striped a$$ ape & will easily spank a Valkyrie but it is damn near unridable as a touring bagger. It won't touch a slightly modded Rocket 3 that can be ridden all day. But somehow it trips his trigger & makes him happy.

Hell, I don't know nothin' no mo' I guess!

To each their own!