Andrew,
It sounds like you have an OWENS pharmacy oval. Does the base have an
Owens suction scar? I have seen pharmacy ovals marked OWENS on the base.
Toulouse dates the Owens Bottle Company from 1911 to 1929 (page 392).
After Owens merged with Illinois Glass in 1929, the mark on their pharmacy
ovals probably changed to the I-in-the-O mark. Tony McNichol and I
presented a paper titled "Dates for Suction Scarred Bottoms: Chronological
Changes in Owens Machine-Made Bottles. at the SHA meetings in 2002.
Contact me off line if you or anyone else is interested in a copies of that
paper. I also have a bib on machine-made bottles available for those
interested.
Peace
George L. Miller
URS Corporation
561 Cedar Lane
Florence, New Jersey 08518