I have to agree with Art...
I assume....it's like in the 1:1 car world,
the sedans and hardtops are embraced by car enthusiasts, because they're cheap and easy to work with, I assume there are more customized versions, then that there are "restored to factory specs" examples out there, I bet everyone here knows some guy who's tinkering with one, they're like big scale model kits, lots of aftermarket parts available and you can even drive it, how much better does it get?
A convertible as nice a car it is, is rare due to fewer produced and even fewer who survived the tin worm, so much more expensive and also the structure and weight of a convertible always compromises a good performance/drag setup.
So IMHO a convertible kit, if released will sell to a small contingent of car modelers, and after a few dozen or so years will bring top dollar on ebay, due to is rarity.
Again I'm assuming here, you guys have to remember I'm looking at this from a distance.