Paint stripping tool setup: I use this Makita sander with an 8″ 3M strip it disc to remove paint, bondo and rust without removing metal. If there are several layers, sometime I use aircraft stripper to soften the paint first. A plastic puddy knife gets some of the paint off and then this sander just balls it up and throws it on the floor. Messy but effective and won’t warp your panels.
The 3M discs are hard to find but they are sometime available on ebay here
I use a similar contour guage all the time to duplicate shapes or check body contours from side to side.
My TIG machine is the Miller Diversion 180. I’ve changed the ground clamp to a magnetic one and changed the torch and cable too. It’s a simple machine for an amateur such as myself. I much prefer it over MIG welding autobody sheet metal.