Just make sure no matter how long you have to wait to find yourself a seat, don't give in to something else that "should" fit. I have a 72 Demon and had been waiting for a very long time to find a back seat and finally I gave in and bought one out of a 72 duster. When I got it, it looked absolutely perfect but then, when it came time to put it in, the connecting points were off just enough to.................not fit.
Good luck!
Sounds like you just need to tweak some brackets.
looking for a regular rear seat for a 73 duster