Thanks for the info and tips. The letter is "H" on that side. Using the guide, that means 1962. Does that sound about right? My great-grandfather was definitely alive & shaving at that time.
I already did 1 round of scubbing bubbles and a seperate round of oxi-clean in that picture above. Will give it another shot with scrubbing bubbles since that seemed to do more than the oxi. Thanks everyone, looking forward to getting my 1st shave in with these!