@RJ Here’s a video by our own @Jason Burton on fitting a thumb safety to a 1911. I’ve fitted a thumb safety, installed a fitted beaver tail grip safety on a 1911 before. The thumb safety took two tries due to youth and inexeperience. As long as you go slow and aren’t afraid to throw away a mistake if you screw things up and something doesn’t pass a function test then think it’s a reasonable and fun task to learn learn on your own.
Also Hilton Yam at 10-8 performance is offering reasonably priced 1911 armorer classes online/over zoom (they’ll resume in the fall) now which you might be interested in if you get a 1911 since you enjoyed the Glock armorer class.
https://www.10-8performance.com/training/