Does anybody know of where I can find a compatible replacement headphone socket? (To solder)

I would be eternally greatfull for your help.

I would think once you take the case apart and see what the headphone jack looks like, you could take it to an electronics parts store to match up, or search on Google for an online source.

Another avenue would be to find a DOA unit for cheap on eBay and buy it just for spare parts.

I think it would be much of a hassle if you solder it yourself. I would recommend buying a brand new piece instead. It saves you a lot of time.