OP: Bet they’re a standard thread. A thread gauge will be a few quid, then once you know the thread pitch and size, some decent steel machine screws will only be a few quid more.
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A box of difficult to replace sewing machine spares that belonged to my aunt. Took about £100 and a year of looking to replace them. Live in landlord at the time: “No, I didn’t touch them”. He was busy storing stuff in the loft at the time, I looked up there several times but couldn’t find them.
Landlord three years later: “Were you looking for some sewing machine bits once? I just found these in a box of my stuff in the loft”. After I’d turned the air blue, he said “I don’t see how this is my fault”.