These tongue and groove pliers have the Champion De Arment, Meadeville, PA on one handle and Channellock No. 410 on the other. Patent awarded in 1934 which places these sometime after that. The meaning of the "H" on the inside handle is unknown, but possibly a date code.
Champion De Arment
Full Plier Image:
Close-up of Jaws:
Handle / Grip Pattern:
Plier Manufacturing Date Range:
Sunday, December 31, 1933 - 19:00