While I appreciate the sentiment, my knowledge falls far short of "boundless". It's just what I suspect you'd probably find if talking to another S&W 3rd gen armorer with a little experience and having repeated the class a few times.

The disconnector fits all the 3rd gen's. It's usually a drop-in part, but ...

Installing a steel disconnector would still require the same armorer inspection and bench checks as when installing the plastic disconnector, making sure the new part functions properly and all the usual safety checks are passed. (And bearing in mind the steel one might not be one that's as precisely sized for that particular gun as the newer plastic one, such as if it's slightly too long/tall.)

Some of the things that could involve a damaged, worn, or out-of-spec disconnector (and some other causes, of course), or one not properly tensioned by its little spring, could be: Failure of the hammer to cock into single action; No pick up in double action; Gun will fire on 1/4" disconnect (out of battery); Skips double action. (In older guns, if the hammer falls to half cock in single or double action it could also be the disconnector ... or the hammer, drawbar, sear, trigger or a light or short mainspring.)

It would be probably be better all around if you had a local gunsmith who was familiar with S&W TDA guns who could inspect the gun and not only check for any other unexpected damage, but check the usual things (disconnect, rocking the hammer in DA, no push off in SA, decocking timing, hammer bind, firing pin movement and the safeties, etc).

If you were local to me I'd check it for you, as I'm curious how the hell someone who owned the gun before you managed to break those parts.

BTW, even if you're curious, you don't really want to remove the mag catch nut, spring and body from the frame (unless it isn't working or has also been screwed up and damaged). The plastic mag catch nut/button is a 1-time use part, meaning it's only intended to be installed once.

If ever removed (meaning for repair), armorers are told to replace it with a new one. It snaps over the left/end of the mag catch body's pin by virtue of a raised inner ring in the plastic nut, snapping over a corresponding raised ring on the mag catch body pin. Prying it off can mean it won't fit back over the pin's ring snugly enough to remain affixed to it. These are pretty durable parts, but they aren't "proof" against curious, well intentioned but inexperienced kitchen table tinkers.

The mag body part is getting very difficult to find, although I've seen the plastic nut and tornado-shaped spring (which does have a "right" orientation underneath the nut) sometimes show up at Midway.

You have a gunsmith near you who is familiar with these guns?

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Ret LE Firearms inst & armorer