I wonder... many of Picard's enemies seemed to know the hero captain's starship in and out, including two-bit villains such as the Rutian terrorists. How difficult would it really be to duplicate a working starship? Rather than a semi-inert mockup like in "Mark of Gideon"?
Why duplicate one when you could just pick up one abandoned in space?
I'd guess that if Starfleet had any proprietary technology it was all copied by the Ferengi after they got a hold of USS Stargazer and it sparked a proliferation of black market Federation military-grade equipment and arms...