The factory rails that S&W install on the railed models are made by Troy Industries. I have put Midwest Industries rails on a few before. They usually costs about twice what you spent on yours, but no worries when it comes to fit and finish. It's one of those things where you get what you pay for.

I would think it would be easier and a lot less trouble to just pick up one the other more quality rails than to replace the delta ring and all that. The Midwest Industries I installed required simply just pulling the D-Ring back with a strong grip and it dropped in.