In the spirit of forums everywhere, I'll give the opposite advice of Superhawk
I just painted my 76 back the original Magala Red. It is a SoCal one owner car, always garaged, zero rust or even a hint of rust anywhere including the hell hole and battery tray. The jambs and inside trunks were very nice.
I did the body work, the high build primer coats, and all the sanding including the final sand prior to sealer and color. The car was pretty well disassembled. Windshield and rear window glass were left in, but that's about it. Doors disassembled, rockers, all trim, lights, headlight doors, etc.
The hood, rear trunk lid, engine lid, and headlight doors were painted off the car, There is no way (IMHO) that you can get around the three big panels and still keep the gun the same distance from the surface without removing them from the car. No need to build stands. Use sawhorses.
Here's a video of my buddy Paul applying the sealer and color...
Painting the 914This is a single stage paint.
I see no reason to go to bare metal (IMHO) if the car is in original paint ONLY and if it is in good condition other than fading. It's like having one more primer coat to block out. If you find some problems when you block out the original, take those sections to bare metal. There will be no problem with paint compatibility since you will be applying multiple coats of catalyzed high build primer and a coat of sealer prior to color.
Here's the finished product cut and buffed and reassembled...
Here are the jambs and frunk in original paint compared to the respray...
Take your time to have your paint supplier carefully match the paint you are going to apply to the body with the jambs or other areas that the sun hasn't weathered.