What kind of play? Pliers tip side to side or at the main pivot side to side play?
Although you said it's difficult/expensive, I'd try Gerber's warranty service first; it is excellent service, and since they're two tools maybe shipping and handling will be "cheaper" as it would be one package. If it is still not to your liking, you may try thishttps://forum.multitool.org/index.php/topic,66808.msg1283754.html#msg1283754It has worked on two of my MP's, a PST II, and a 2nd. Gen. Wave which had loose pliers pivot. Good luck, and let us know when you resolve!