“After filming, the Bird of Prey model disappeared, which may account for the Romulans showing up in Klingon D7 cruisers in the third-season episode “The Enterprise Incident.””
Rumor has it that the OG model was destroyed by the creator as part of a union dispute.
"The original model Bird-of-Prey was destroyed by the model maker, Wah Ming Chang.
Herb Solow and Robert Justman’s book Star Trek: The Inside Story explains that a union grievance had been filed for a non-union contractor selling props to the production. After the one appearance was filmed, the model was returned to Chang without him being paid or receiving credit for his work and he destroyed the model himself."
https://www.startrek.com/news/forgotten-trek-creating-the-romulan-bird-of-prey
“After filming, the Bird of Prey model disappeared, which may account for the Romulans showing up in Klingon D7 cruisers in the third-season episode “The Enterprise Incident.””
Rumor has it that the OG model was destroyed by the creator as part of a union dispute.
https://scifi.stackexchange.com/questions/127159/was-the-use-of-klingon-ships-by-romulans-ever-given-an-off-screen-explanation#127170
"The original model Bird-of-Prey was destroyed by the model maker, Wah Ming Chang.
Herb Solow and Robert Justman’s book Star Trek: The Inside Story explains that a union grievance had been filed for a non-union contractor selling props to the production. After the one appearance was filmed, the model was returned to Chang without him being paid or receiving credit for his work and he destroyed the model himself."
Dude, I love Trekkies