1974 Duster t-top conversion
I believe the dodge Aspen plymouth volare t tops were done by the now defunct cars and concepts as were the dodge magnum tops. A lot of the t top conversions on most cars in the 70s and 80s were done by C&C. Dodge Daytona, second gen camaro/firebird, fox body mustangs & capris. Even the pontiac fiero. Good luck finding weather stripping, and getting it to seal. I think subframe connectors and torque boxes would be enough for this. Heck, on the FWD daytonas they never even modded the chassis under it. I would look at whichever T top conversion you can readily find repop weatherstripping for and start from there. Measure roof widths and curvatures from all those different cars if you have access to them. You will need to get the glass and T bar frame from somewhere to make this. Preferably glass that has a similar curvature as your duster roof, or this ain't gonna look good.
Good luck.