I have a MIJ Jackson PS-4 (mid 90s) with a Jackson licensed FR named JT-500 double locking. On the plate for the handle you have only threads. Then you need to screw in the mounting ring, then screw the handle inside that ring. Handle was either very wobbly or too tight, so it was blocked from rotation. And every move could unscrew the mounting ring with the handle at the same time.
This FR handle from HB was easy to install, it suits almost perfectly. I had only to put a squished spring inside the barrel before putting a handle in place, so it is rock solid and have no any even minor wobble.
Thanks for saving me from buying a whole new FR :D