Little more info I spent 425.00 on repairing the trap basically all new insides have some extra parts to go along new main spring and a few other parts. The Retro I bought new and is complete and worked fine.
No you have to remove the retro to throw doubles, I rebuilt the trap myself I have worked on them over the years I have talked to you over the phone Roger asking for some troubleshooting help many years ago, The parts came from QRP and it does work fine. Did the rebuild about 5 years ago threw about 2000 targets on it took out of the pit and it has been in stored in machine shed. Side note Roger I shot doubles with you at the Grand a few years back. Don't know if you remember I was leadoff Bobby Chambers was also on squad plus 2 guys from New Jersey who were shooting nitros, they wanted to raise the targets so high you said if they go any higher they could shoot by themselves.