Let me count the ways.  So I bought a rebuilt brake booster from RockAuto: A-1 CARDONE - 535104 (53-5104) - Power Brake Booster $84.79 + $25.00 core = $109.79 I open the box and it's unpainted bare metal, and the metal that is exposed is deeply pitted. This thing was apparently a boat anchory rusty mess that they bead blasted back to "shiny". It's clear that someone sent in their completely tired worn out old dead booster as a core. There are also clear signs of physical abuse. Almos