I enjoy working on the old chassis and face plate for reuse. Even if they're beat up and bent, as they usually are. Stripped screw holes are easily rethreaded and deburred. IEC sockets installed. Metal straightened.
But then, I rebuild for myself, and I accept the "patina" these old amps have.
To me, it's worthwhile to invest a couple hours on the old chassis and faceplate.
As for the electronics, jacks, wiring, etc, hell no! WOAD and Wattsabundant products and silver plated Teflon wire are a requirement.
Wait till you all see the PL2000 Series One preamps face plate that came out of San Francisco. Pretty damn rough, but I'm going to use it on the next preamp build. It'll look good (to me) sitting on top of the Pro 700, square corners and all.