I happen to have data on various shellac releases from the 20s to the 50s. Sometimes I find the release dates, sometimes not.
Now I have a question that boggles my mind: Yesterday I added some polish compilations and found a source on one of the cassettes that said “released prior to 1980”. I also found a catalogue for shellacs from 1946 of one label; that would mean that every releases I couldn’t find a date for would be released 1946 latest.
Do you think it’s better to insert 1979 and 1946 in those cases than to leave it open?