Not being a serious collector I am not much interested in originality. I am far more concerned with whether I like the gun than if it's correct in every detail. I would much rather have the gun in the configuration I prefer than maintain strict originality if the original features are not to my liking.
I am not alone. Pictured is a pair of 1950 44 Targets that were shipped several months apart in 1955. One went to St. Louis and the other to New Orleans. By 1970 they were together under one roof and the owner returned them to S&W for modification.
Both started out with 6.5" barrels. One had a replacement 5" barrel installed and the other was cut to that length. Makes me think this was the very last 5" barrel in the parts bin since they wouldn't have cut the second one had another spare barrel been available. The replacement tube was not stamped with the serial, BTW.
In addition to the barrel modifications, the owner had the factory swap the triggers. The standard narrow, serrated units were replaced with the wide, smooth versions some folks call "combat triggers" (although I am sure that's not any sort of official designation). It also appears that "semi-target" hammers were installed, as well.
I love the guns the way they are and don't lament their loss of originality for even a moment. Would they be worth more money if unmodified? Probably. But I don't care.
When I bought these, I was reminded of a Model 28* I had back in the late 1970s that also wore the smooth trigger some previous owner had put in place. I realized that I liked this feature and bought a bag of them (literally, a member here had a bag full of smooth triggers and I bought them all for a pittance). I have swapped them onto most of my 27s and by the way, all but one dropped in and worked fine without special fitting.
In your case, if you are interested in the collector value of the gun (as it sounds to me) then simply acquire the correct parts and return the gun to original configuration. You could likely find someone willing to swap his parts for yours and a previously mated hammer and trigger will doubtlessly drop right in.
*Yes, it was a Model 28. Not a Model 28-1 or 28-2 it was a Model 28. That means a Model 28 NO DASH for those of you unable to figure out what Model 28 means.