Greetings,
I also have a 54TF. Is the gearbox still noisy in first and reverse? Or is it more quiet now after having the laygear replaced? I rebuilt mine a few years ago and did not like the limit that 1-2 the shift rod had on the 1-2 slider so I found another one that let it engage better. Also does the shift handle move back and forth under off and on throttle?
As for leaks , there is a rear crankshaft seal modification that works well if directions are followed to the letter. I did this to mine when I built the engine and the only leak so far is a slight seep at the back of the gearbox.