I put a Bigsby B5 kit on my partscaster last November and quickly grew to dislike the jag/jm bridge included. I bought a Mastery m1. For a while, I liked it, but I started to have problems. The saddles would rock when I used the bigsby, but unlike the jag/jm bridge, the mastery is supposed to stay put! I was told by the fella at mastery that this was normal on a b5 tele. It wouldn’t bother me that much, BUT it made a clicking sound that I could NOT abide. I tried many many many things to fix this. Too many to list here. Also, the saddle screws wouldn’t stay put, and the saddles would lower themselves. I’m not rough with the bigsby, but I use it often. SO, a friend on another forum sent me his mustang bridge that he was not using. I installed it tonight and it’s great!! It’s supposed to rock, and I hear no clicking sound through my amp. I also lost no sustain. I’ve actually gained more. That’s an unexpected bonus. I installed it with the screws facing the pickup for easier intonation. I think I may be selling a mastery bridge soon! Thanx for reading!