Haven't been able to drill a hole in the concrete yet but hopefully in a few days. THANK YOU ALL SO MUCH for sharing all of the experiences with type of issue on here! I'm very confident this will solve the problem given the state of the buss bar, etc.
The building was a full-time machine shop for decades but was my grandpas storage facility for his car collection for 17 years unheated. At the last few years before he passed away the roof went bad and started leaking, which raised the humidity and started corroding everything. We have totally redone the entire facility but never messed with the electrical because everything checked out with a meter.
We wouldn't have figured this out cheaply nor fast without all the help~
Sincerely, thank you all so much...