Definitely looks like a 3 phase panel with a missing lug to me.
CH single phase panels use the same insulator and bus support, but the feed lugs are always on the 2 outside positions. Notice the burn marks where the lug used to be...
The genius that installed the circuits apparently didn’t believe in ground wires because only 6 out of about 60 circuits actually have a ground wire connected to the grounding bus bar. All of the other circuits coming have been grounded through the metal conduit runs.
