I found a box of 24 of these at a thrift store and was wondering if anyone could help me find a date and maybe what they were used for? Thanks in advance
They were made by Owen-Illinois, which dropped the wings on their symbol
<(I)>
making it
(I)
in the later 1950s, from what I recall.
The 6, as it sits where the date-code usually sits, probably, then, represents 1966, while they were still using the Duraglass branding.
I'm surprised they're only embossed Patent Pending, and not Design Patent Pending. I thought they were still using the Dgn. Pat. Pnd. info into the 1960s.