I bet this installation once had a doghouse, and yes, I'd agree it's circa 1930. These appear to be "meter service cabinets", which date to the time when meters were still required to have a disconnect and overcurrent protection on the line side. I think I read someplace that this requirement ended with the 1931 NEC.
The meters we see are socket-base (they look like GE I-60S), but they are attached to adapters. Both the socket base and the modern A-base were standardized in 1934, and these standard dimensions likely did not exist when this equipment was manufactured. Pre-standard meters were not weatherproof, so why should the cabinets be?
Note the sealing hasps near the top of the equipment, since both metered and unmetered conductors are accessible inside.
There is a schematic of a meter service cabinet
here. And note the legend, "single fuse". This is what you used if your inspector didn't like fused neutrals!
