Gearbox rebuild questions

[Keith Andrews]

Syncro brass rings:
I believe these dont have new replacements??

Are there 2 housings/ main shaft versions?
I have 6 old boxes, 1 has a metal insert for the main front bearing that sits the main bearing further into the bellhousing. If this main shaft is put into a non 'insert' case without gaskets on the covers over the mainbearings at each end (or very thin gaskets) the main shaft will bind up on reassembly. Thicker gaskets and its ok.
Yet a std case that doesnt have the front bearing metal insert, will not bind even if there are no gaskets???

Thrust Bearing shaft/bushes:
These are usually baddly worn. We tested a shaft and it was not a hardened rod. Are these normally built up with a mig welder then turned down on the lathe? Also replacing the bushes, reeming to fit.

Storage of rebuild gearboxes:
How are these stored?
What is used on inside internals to prevent any corrosion for long periods?

Cheers
Steps