>>64128860
Walther PPK and Beretta 21A are definitely smaller, not 9mm but certainly carry oriented. Springfield XD-E is about the same maybe a bit thinner and smaller. Sphinx SDP Subcompact too and that's a double stack. There are probly others, if width isn't that big a concern there's a whole niche of subcompact DA/SAs like the P99C, RAMI and P30SK.

Anyway 3913s are rad, check Numrich
https://www.gunpartscorp.com/gun-manufacturer/smith-wesson/auto-pistols-sw/3913
https://www.gunpartscorp.com/gun-manufacturer/smith-wesson/auto-pistols-sw/3914
eBay sometimes has little oddball stuff too from parted out guns. I don't see 3913 parts at the other usual suspects unforch

I thought you could just take out a spring under the ejector or something to make S&W 3rd gen decocker only, but a 5 second search shows people talking about milling slides so I guess I don't remember good