I have a model 10 that I fitted another barrel to as well as a model 19 cylinder. I have not fired a bunch of hot loads through it and wouldn't even if it was a completely stock model 19. But after 100s of normal 357 loads (158 gr cast over 6.2 unique) I can't measure any stretch.

But, if you look on ebay you will notice some parts bring good money. If you are not setup to do the work yourself. I don't think it is worth it. My model 10 conversion works for me, but it will not be worth much with even added adj sights. It is just a truck, boat gun.