Really weird but interesting stuff!
The top center DIII fuse is missing the key ring, meaning fuses up to 63 amps could be used!
The three single pole breakers (maybe Siemens?) next to the 1+N breakers (a style I've never seen before) scream 3ph too!
But why on earth the NEMA 5-15 receptacles?
That stuff seems to have been abandoned and partially demolished with all those cut wires.