How to identify Roadster Transmission - And detgermine if it would need a welded 5th gearr

[SOUPY]

Hard to tell exactly from the pics, but is the inside bearing surface perfectly smooth? Maybe just a reflection of gear oil where the bearings ride?

[JT68]

Were these transmissions raced possibly?

Those 5th gears have had a very rough life. In addition to the overheating Dave mentioned on the pressed gear, the inner bore appears brinelled on the splined gear. No reliable/practical way to fix that. (if you try to hone it there will be too much bearing clearance which causes them to pop out of gear)

The overheat and loss of press fit was probably due to the minimal clearance (.003 isn't much) on the press-fit gear.

The brinelling on the splined gear indicates excessive load or starved of lubrication or both.

I'd suggest you find a better 5th gear (preferably splined) rather than trying to repair either gear. (sorry I don't have any extra 5th's)