I don't know about Copper's or any other on line store, but I do know about H & Y Electronics. Bought one of the Magnum S45HP's, had them do the conversion and a tune & peak, Just sent it to RF Limited to have it fixed. H&Y sent it to me dead key of 2 watts on low and 25+ on high, max recommended on high is 18 watts. When I sent it back to them it took 2 weeks for them to return to me with no AM output. I talk to Mr. Sam Lewis at RF Limited, told him my story and he had me send it to him to be repaired. I know he had a talk with the tech at H&Y, not sure what was said, but the tech didn't sound happy when I talked to him. I don't usually do any kind of post, but I wanted to relay my experience so maybe it will help someone else.
Thanks,
Gascap