First of all thank you for your service to our country. Lots of vets on this site and we're proud to have you join us. The upholstery route would be my choice as it is a skill that's not too easy to come by anymore and if things slow down in the hot rod, boat, custom car business you can always look to do some custom home furniture work.

Ditto on the welding - I'm always welding something for someone. I'm surprised the number of 55+ folks who still have a welder or two in their garage. I still use arc and gas for various projects.

Good luck and thanks again!
Glenn