When I stripped our '72L to bare metal, I used Aircraft Stripper (sold in a gallon can). And I only chemically stripped to within 1" of all edges. Reason was, the chemical stripper can creep around corners and under panel overlaps. Then weeks or months later, after a repaint it bleeds back out.... I used a sanding disc much like was shown to remove the unstripped edges of old paint. There were three different colors in there.
Also found what looked like 'factory-bondo'; a light blue blob covered a huge oil-can dent on the front fender tops near the windshield. By legend, Panteras were shipped in the holds of freighters and stevedores routinely WALKED on the cars to get to the other side of the hold. The distributors in CA fixed things as fast & cheaply as possible so the brand new cars could be sold. Aircraft Stripper slowly removed the filler-blob, and a really hard punch with my fist popped the dent up into its original position with no filler at all needed. My knuckles healed up in a few days.
I was told by a pro that much the same thing happens with wholesale sandblasting of cars. If you escape panel-warping, the residual dust from blasting NEVER completely comes out of the nooks and crannies during cleaning. But some will come out during subsequent spray-painting and screw things up.