Maybe it could be a Colt Custom Shop gun. Priced on the high side I guess it would be a low volume, high margin (profit) model costing maybe 1500 to 1700 dollars.
Unfortunately you are way too low.
Why?
Because they would have to retool it (very expensive) and then spread the cost over a relatively few guns. The same problem would face any smaller shops that considered doing it. Notice that the small shops you mentioned make custom guns using existing platforms made by larger companies