Re: JS100 Lo TRS II swap - Definitive Answer
Regarding the trem shim, Wookikrisps, it was a bit of trial and error as I admittedly didn't take the time to research it to the degree I likely should have. What I did research and learn is that the trem blocks should be shimmed in pairs with the outer two E strings shimmed the same, the A-B strings shimmed the same and the D-G strings shimmed the same.
I purchased several different sizes (005, 008, 010, 012) and tried different shims until I no longer received any fret buzz. The JS100 has a 250mm (9.8") radius neck. I believe I ended up with the E strings with 008 shim, the A-B strings with 010 and the D-G with 012. Those that know how to do this will likely correct and tell you the proper way to do this to achieve better results as I'm not super finicky about action but that's what I ended up doing. There was a lot of fret buzz on the D-G strings and very noticeable on the other strings without any shims so it does need to be shimmed to achieve the action you are looking for.
I hope it works and I look forward to seeing your pics!