I'm finding this a bit hard to follow. A 3.5 cab sells for between 195K to over 400K for a fully restored example. I imagine that without the soft top, a new interior might be 25K - 35K, which is enough money, but is maybe 10% of the car's value. Unless you can find a perfect used interior, which seems unlikely, why would you go this route?
I'm not trying to be critical - just wondering.