Just got a call from an old friend asking if I could take a look at his old DOD-surplus filing cabinet, which has one of the "butterfly" S&G locks (with a secondary turnpiece in the middle of the knob that holds the fence away from the wheel pack until the dial is turned to a neutral position, to prevent manipulation). It's probably been 20 years since the beast has had any maintainance or a combo change, though it hasn't been used very intensively over that time.
I seem to remember that there were two or three models of these. I've never worked on them, though I know my way around other safe locks. I seem to remember that the anti-manipulation mechanism involves a complicated cam...
I'm trying to dig out my literature... But if anyone's got tips on what particularly needs to be done (or not done!) with these, or reemembers when they were last covered in LL or NL, I'd appreciate the pointers.
In particular: Are replacement parts still generally available? Were these key-change or hand-change? And -- if it turns out that it's on the edge of catastrophic failure -- how hard is it likely to be to swap in a modern replacement?