Up to you if you want to sell them but I think you would be crazy. If you do decide to sell then I know a few people who may be interested depending on the models and the price you want.
You can use ANY synchronous ac servo motor on the AB drives as long as it has the right feedback/commutation and is within the drives specs for current and voltage. I bought a big motor that I knew was not suitable for the AB drives due to the resolver, I also bought a tiny motor that had a suitable encoder on it, I swapped the encoder onto the big motor and aligned it and its perfect
Let me know exactly what model drives you have and what model motors and I will be able to tell you if its possible without adaption to use them.
Hood