PDP-11/45: Teardown and corrosion remediation

Had a little more time to work on the PDP-11 this weekend. Mostly going after some corrosion on the CPU cabinet and H742 power supplies. Tore these down, sanded down the corroded bits, then hit with a satin finish Rustoleum rattle-can which dries to a reasonable approximation of the original powder-coat.

Neon indicators on the H742s are dim and flickery, so ordered some replacements for these, too.