1963 Valiant differential rebuild kit and ring and pinion gears

I'm wanting to restore/preserve my '63 Valiant and the rear 7 1/4 differential is completely worn. I know it's popular on the forum to replace these and I'll consider it if I can't find the parts to restore this one but can anyone point me to where I can find ring and pinion gears (maybe 3.23 or 3.55 or even replace the 2.93)? Also can anyone recommend a good rebuild kit for the rest of the diff?

Thanks