I had the shifter out of the FM-146 in my choptop but it’s been so long I don’t really remember what it looked like. Think it was a bit different than what you have there, mine had a little rubber boot that was all tore up, I cut the shaft, ground a flat and drilled holes to make a stub and fit a boot from a ZF-5 on and built a new shift lever. That kinda doesn’t look like it ever had that sort of boot… think that plastic part is supposed to have a spring above it to keep it pushed down as a seal but I could be wrong