I assume by "button batteries" you are talking about the small battery on the circuit board that keeps the model memories refreshed and real-time clock going? (i.e. NOT the main batteries to run the transmitter).
I have done those replacements on JR X347 JR X388
I could probably do it for you and only charge for shipping and parts.
Please send me a message with the specifics of the radio models (e.g. X347) and how many.
I hope you are not in a rush. (PS: All of the model memories are lost if your battery is replaced).