I am in the process of purchasing a police trade in P226 9mm. I am not familiar with the history of Sig pistols. But the slide says that It was made in Germany. The clerk at the local gun store said that it was manufactured in 1991, or so he believes. The pistol seems to be pretty worn but the barrel seems to be in fair condition and everything seems to be functioning properly. I ended up spending around $350 for the pistol which I hear is a reasonable deal. Today I order some replacement parts to include, barrel, recoil spring, grips, and new night sights. Is there anything else that anyone could recommend replacing or upgrading ?

good find

a good link to check out on the sig forum https://www.ar15.com/forums/Handguns/Must-read-for-German-Made-SIG-220-226-Guys/14-175841/

Out of curiosity, why did you replace the barrel? Did you shoot it for accuracy?

Rethink buying the parts.  Send the gun back to Sig.  The have a factory sponsored program where you can have work done    They’ll replace the night sights. Springs. Do a function check etc for what it’ll cost to buy just the sights. More or less.  While it’s there they can replace the barrel and refinish the finish should you like.

Another case of, "I didn't do any research and bought a wopped out gun to throw money at" when you could've just bought a like new or factory refurb model for the exact or even less money total.  Sigh*

This

Replace the pins and springs.

Where from?

recoilgunworks, sportsman'soutdoorsuperstore, AIM, etc etc.  Nearly everyone has trade in Sigs right now

Not sure what the other guy is talking about, $350 for a turn in 9mm is a good price, but I'd expect a lot of visible finish wear. I dunno why you'd replace the barrel though, especially if you haven't fired it yet.

If it was for self defense, I'd pick up a parts kit:
https://www.topgunsupply.com/sig-p226-9mm-parts-kit.html, then shoot a hundred or two rounds to ensure function. Probably buy new mags too and use them to test. The SRT is terrific, and easy enough to install yourself. But if you're happy with the stock reset, don't bother. If you wanted to go a little overboard, you could replace the extractor and spring, but I think barrel replacement without shooting first is over the top unnecessary.

If it was just for range use, I'd keep it as is, maybe change grips to your liking. Then shoot the snot outta it.

Please link a p226 9mm, which is what we're talking about.

Beware that that kit shows the "new" style trigger bar spring with the circular loop in the middle.  That spring doesn't fit under the original factory grips (checkered style) of an early 1990's P226.  You will have to replace the grips with the newer pebbled finish style or an aftermarket grip to use that spring.

I have heard that the split roll pins are getting harder to come by, so I would keep the new ones aside unless there was a compelling need to remove the breech block or firing pin.  They don't just crack into pieces and go flying out of the slide, the repeated firing forces seem to cause the pins to bend, the inner pin starts to lose tension and it begins walking out of one side of the slide gradually.

Good points.  I overlooked that he believes it to be a 1991, which would be stamped not milled. Yeah, parts in general for that are gonna be hard to come by.