DeVilbiss GFG-513 spray gun complete disassembly, rebuild and restoration

I bought this spray gun in 1990 and painted 10-20 cars with it. Since then, it had been lost until now, when it was found among scraps at my mother's place. This DeVilbiss is completely seized up and clogged. This model, GFG-513, is no longer in production, so it must be disassembled carefully without breaking anything.
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