Probably right. I just checked Numrich for a common high mileage wear part on 59/6906.....the extractor.I'm not sure but you do bring up a good point. Common replacement parts would be fairly limited to just recoil springs?
I was right btw, cheap 6906!
NO parts for the 6906 available!
Only an after market 3 piece spring tune up kit for the 5906.
Back in the 5906/6906 days S&W didn't sell replacement parts to individuals, lots of those parts required some minor fitting. They sold parts to departments with certified armors and retailers with certified gunsmiths. That probably left a limited number of parts available in the public sphere when S&W abandoned the Gen 3 auto pistol. For me that makes a 5906/6906 cheap gun a good buy as long as you accept that when a major part fails the gun will likely become a wall hanger.