I used stuff called Jet Strip from O'Reiley's (About $20 a Gallon)put it on with an old paintbrush, Wait 10 minutes(The paint will start bubbleing up), Use a razor blade to scrape and the laquer shaves off like chocolate. Then repeat for the layers of primer.
some friends and I did the Cab of my 53 in one evening. The evening before that I had spent several hours on just one little spot.
(See previous post http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=4;t=001373 )
But be sure you do this outside on a breezy day or in a shop with good ventilation we had a 6 foot tall fan running in the back wall of the shop and it still made me light headed if I was between that stuff and the fan.
After we got the paint off I hit it with some 80 grit sandpaper in the DA sander to clean up anything the stripper didn't get and then went back over the whole cab with 120 then 220 sandpaper to get it really clean and smooth. That's only after you Bondo or weld up the holes you find when you get it down to bare metal.

You Can Do it yourself!
Up til we did my cab I had a Phobia of body work, now I'm rareing to start work on the other parts of my truck.
MONGO

Mongo's Garage
Vintage GM Truck's & Parts
https://mongosgarage.com