I am an amateur when it comes to amp repair, but like quit a few others I've seen on these forums, I have a love for doing this kind of stuff and want to become more than just a hobbyist.

First off, I'm 47.
In high school, I took a couple of electronics classes at the local vocational school back around 1980... (Through the years that experience has served me well as a musician and at home "jack of all trades" so to speak.) When I graduated high school, I joined the Air Force and picked a career field that fell in line with my interest in electronics. Unfortunately, my math skills were not strong enough and I washed out of that field. So my military years were spent as a Fireman, instead of what I really wanted to do.
After the military, I worked a few jobs. Some were electronics oriented, like alarm installations, but I never went back to school or took it any farther than that.
I then went on to be a somewhat successful musician for about the next 20 years. But I'm getting older and would like to make a change. The more I thought about it, the more I thought, "why not finally learn, and the correct way, mind you, what i always had a love for. Electronics"?
At my age, I'm not looking to become an electrical engineer working for NASA by any means, but I always loved tinkering with my amps and working on guitars. As a matter of fact, in the early days of eBay, I used to buy guitars (Gibson, Fender, EVH Music Mans etc) that were pretty beat up, fix them up and make them look practically like new and re-sell them. I actually got pretty good at it, and made some excellent cash doing it. At the same time, it fed my love for acquiring new guitars. lol
Anyway, my thought was to get enough education, where I could start doing amp repairs and mods locally. Now a days, I own a home in a small town just west of Kalamazoo, MI and thought, surely guys around here could use a decent amp guy?
Instead of just asking questions and diving in and figuring it out, I'd like to take it to the next logical level.
Where would you experienced amp guys suggest I start? I don't think I would probably need 4 years or more of school would I? With the internet, stuff on DVDs and the vast wealth of experienced individuals in the various forums, it seems like I could accomplish a lot even from home. Over the years I have collected a decent collection of tools, like a couple of Tektronix O-scopes, probes, meters, DC power supplies, a signal generator, a variac, etc. etc. As well as some basic educational stuff like a bread board, and trays of sorted and assorted electrical components, jumpers etc.
What would you recommend? A 2 year school and specialize from there in tube amplifiers? Not sure of which direction to take. I certainly would appreciate your real world opinions & insight.
Thank you,
-Chris