Hi Gary,
Welcome to restoring vintage Erector Sets. I think you will find it quite rewarding. Every time I restore a set to it’s original glory, I feel I’ve contributed to continuing the magic of A.C. Gilbert.
There are different viewpoints on restoring. On side feels leaving it untouched is the route to go, rust and all. The other side strips the paint and repaint’s/refinishes all of the parts. I think I’m somewhere in the middle. I like to keep my sets as original as possible with careful cleaning. For my model builds (which I use extra parts, not from my set collection) I will strip and repaint the parts.
There are different processes as well. Probably too lengthy to discuss here. I do plan on writing an article for our newsletter on restoring parts and the process I use. To answer your question regarding removing the lead paint, yes it is safe if you are careful. Don’t try scrapping or burnishing off the old paint and get it air born. Use a liquid paint remover like “Citristrip” which is quite safe and smells good. I use “EVAPO-RUST” by Orion to remove rust from parts, as it is safe for the environment and the user.
Evapo-rust
This website has a lot of good information on many topics:
Girders and Gears
I hope that helps and good luck restoring! Don’t forget to look for my article in an upcoming newsletter.