I find FPE panels here & there... I came across some tract houses in San Diego & Oceanside which had FPE panels AND aluminum wiring! (Talk about bad getting worse!), & they were from the early 80's... I think the EC that did the original build must've gotten them on clearance or something
Another peculiar thing I found was a supply house in San Diego which STILL had FPE 100A meter/mains in the box! (You know a good product when it's still on the supply house shelf 20 years later!) Most of the FPE panels I get called to replace are the old 6 circuit/no main style from the 40's & 50's..
Another peculiarty with a specific manufacturer... I've come across 3 or 4 Cutler-Hammer "CH" style panels where the 100A main breaker actually caught fire!
No damage occured outside of the panel can except for some blackend stucco, but it was strange & kinda eerie seeing that more than once, in different cities & build era's at that!
I come across FPE, Square D "XO"'s,Bulldog "Pushmatics", even Wadsworth & Trumbull boxes that are pushing 50-60 years old that are still in basic "working" order & get changed out mostly as an upgrade.... But the Zinsco changeouts are alomst always due to equiptment failure.. As I'm writing this, I just came back from replacing a Crouse-Hinds 100A main that refused to reset.. Albeit there was enough dirt in that panel to grow an orchard.... 5 minutes, a brush & some "Lectra-Clean" & the bus looked new again
Zinsco has made ALOT of money for my company & I!