comments:
I'll second what toaster says. It's probably the same size as the remaining screw in the lower part of the clasp. Take that screw to a local hardware store and see if they can match it. Barring that, if you have a Fastenal store near you, they could probably identify its size - typically identified as the diameter and number of threads per inch. e.g. 6x32, or if metric M4x0.5 Get brass ones to match if you can, but a steel screw of the right size will work. Fastenal likes to sell large quantities of screws since they're really an industrial supplier, but they may help you out. It's probably not practical from a cost standpoint to buy a Screw Chek'r https://www.amazon.com/Screw-Chekr-Thread-Gauge-Checker/dp/B0006NFUJW?crid=1FXKI0571YMOT&dib=eyJ2IjoiMSJ9.GatMo4UcV-SEdzKcugjYYH3AlAds7_nPbd2tzXB8UAk2IOrGLN6XWUNIMinaveu2JJ1h8b8PU1SuT9qVmPoYuzIleQcU7vLei_Xtquabu3iBvLR8TBPcvB8MrCuKHzQwFQlJx-UYKZaK-B0_Mm3zynfqxhGVMregQF_6p02n93r32jvD9-mdRecV5aXKOZS-MHV_dkXf-qUVk_rw2bwe2o_PemKxBCstmejbZgZd968.j-VOk8Zh0l5wsM6Tv4nao4k7iroPjchZ-e5kHjsz8gU&dib_tag=se&keywords=screw+chek%27r&qid=1782067331&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=screw+chek%27r%2Caps%2C268&sr=8-3 because you'd need them in both inch and metric varieties, but that would identify the screw size. Typically a good local hardware store will have something like that, but you can always just try nuts at the hardware store till you find the right size you need and then buy the matching screw.