Most visitors online was 4107 , on 14 Jan 2023
The issue is that this pressed steel plug pre-dates Underwriters Laboratories. All electrical devices sold in the US must now comply with UL standards, and UL's idea of safe distances to metal surfaces and human fingers is quite a bit more than that used during the 1930's and 40's. So these in-line receptacles are sold, but modern versions are quite a bit larger.This is an input that I have seen on various brands of older clocks. I have never seen a source for new ones that are small enough.