I had the same problem (based in UK). Ended up getting a colleague to get creative with attaching a different spec of jack socket that was easier to get (sorry I don't know the exact spec). See this post and also attached photo https://www.openacousticdevices.info/support/device-purchase/hi-do-the-jack-sockets-for-audiomoth-1-2-0-need-to-be-model-sj2-35464a-smt-tr-or-can-4-pole-alternatives-like-in-this-pdf-be-used-thanks

Thanks Seth! In the end I got a colleague to help and he did exactly that, though he glued it to the top surface rather than the side. A good solution and works fine :-)

Thanks Alex for your helpful reply!