A possible clue? Surfacing is a vitreous china bowl made by TEPCO in California (bay area). This maker went out of business, reportedly in 1968. That would leave a narrow window in which they may have produced wares for the nearby Alice's, and most likely handled through a supplier such as Dohrmann. Given TEPCO's demise at that point, it's highly unlikely to have been made for anyone else opening after the movie came out, and TEPCO wares were never used beyond western states. Of course, the china sample is undateable, which leaves the potential of a much earlier user between the 1930's and 1968..but none has been clearly documented so far. Herewith the sample images:
So...it seems possible that Alice's La Honda ordered china in 1968 as part of a planned name change which may have only become effective starting with a new year in 1969. And that could explain the start date on the silverplate tray.