I'm sure I'm not alone, but it seems I keep getting more.
Although "like" pistols, they have been acquired years
apart. My 439, and 459, same year. My 639, and 659,
(square/adjustable,) same year. My 3904 and 5904,
(square/novak,) same year. My 3906 and 5906, (square/
adjustable,) same year. My 1910 and 1914 Mauser, and pre-war Walther PPK and PP, same year. OOPS, wrong
Forum. Is this happening with you?

Nope! I have a number of duplicates (hell, triplicates?), and they tend to be from different years.