While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
Note: This feature may not be available in some browsers.
I think you mean "First Model DA", right? Number 3 was a single-action revolver.
Anyway, they're both quite expensive guns to buy, even for parts. I have a First Model DA (in great shape), but I've seen rusted or refinished beaters on gunbroker going for over a grand.
If you desperately need parts, I believe some companies are making replicas of the No.3 guns (Pedersoli?). With any luck, some parts may be actually interchangeable with the original DA S&W's. But as far as getting a cheap parts gun... tough luck.