There were a few different series of Colt Black Powder cap and ball revolvers (2nd Gen "C" and "F" series and 3rd Gen) and they were exceptionally well fitted and finished.
This set of articles and discussion on the Colt Forum is one of the more complete references I've found for them:
Are the Colt Signature series Black Powder guns considered "Real Colts" ?
I personally think the 1970s era 2nd Generation "C" series and the 1980s 3rd generation revolvers are exceptionally well finished and are arguably the best reproduction cap and all revolvers ever made.
If you find one for $800 in excellent condition it's a deal, and if you found one for $600 it's a steal.
Please send me a PM with the shop's name so I can follow up on this.