Bearstopper, I have a friend who takes the rear sights off and makes 3 screw vaqueros out of Old Model 357s and all of the rear sights I noticed yesterday are setting in his shop in a pint jar. I do not know if any were flattop micro sights but I would feel pretty positive to say that out of the 100 or so sights in that jar at least one may be the one you need. I will check this evening and you can PM me tomorrow and I will let you know. I know of at least one set he took off of my flattop 357 he engraved and modified to Vaquero.