Thank you to guys on my panel board thread.

[fastline]

Thank you to the guys that got a chance to reply. I just wanted to clarify that because the building electrical system has been messed with so much by previous building owners, and thieves got in and started chopping out wire for scrap, we have to vet every inch of wire and prescribe corrective actions. I've found a laundry list of safety items. That panel is not even hot right now. I have recommended a full tear down and inspect. Square D seemed pretty confident they would be able to provide either a compatible breaker solution, or a retrofit.

Very much appreciate all the input I get here! If that panel was hot and doing stuff right now, I could understand the "leave it" approach, but for reasons I need to uncover, there was an overhead conduit that was installed to bypass this panel, but is only powering a single air compressor circuit.