Not sure how you'd use hockey pucks for motor mounts. In the past, the hot topic of discussion was using hockey pucks for subframe bushings, using pieces of exhaust pipe around the OD for "reinforcement". To be honest, putting that much work into making a hockey puck work as a half assed subframe bushing is ******* ********.
Anyway, sounds like you're on the right track with replacing them with stock mounts.