As a Master Tool & Die Maker you should have NO PROBLEMS at all getting into Smithing. I started 35 years ago with no instructions, no videos, just a good mechanical aptitude and some basic hand tools - kind of the learn as you go method. Smithing on S&W revolvers is actually not all that difficult and once you get them apart and study them, I think you will find the actual smithing part fun and rewarding.
There is a good book available - kind of the standard among us hobbyists by Jerry Kuhnhausen and it will give you 90% of what you need to know and the rest should come naturally.
A good gun to start with is something like a M10, M15 or similar. Just get the book, and start doing - you will be amazed at how fast you will learn. What isn't common sense should be able to be found in Jerry's book. After you've mastered one type and style, move on to the next. In 6 years when you are retired, you should be pretty good at it.