Is this a factory Flat Top of a modified No. 28 rear sight
Its either a 24A, 24B or a 24C. Or the earlier Sporting leaf before they numbered them that was modified. When they were turned in flat tops and you have to jugde the quality of the workmanship to tell if it was factory or not. Either way the slide is a homemade replacement.
Morning Bob and your knowledgeable input is much appreciated