Yes, it looks that way. Just love puzzles
So based on this we run 120 volts AC and it says 120 volts depending on the installation. Just check to make sure she be a 120 volt AC installation. If that checks out, then standard current we use now should work to power it up. Personally, I would disconnect everything to main panel before the power up. Mark all the connection etc. If the panel powers up without issue, connect the peripherals it feeds one by one. Keep a fire extinquisher handy!
Things like this make you want to quite your day job and just go work on the sub!