Identify the postmark and you might be able to find a company name that fits from an old almanac or annual report.
If the first letters are M A, there are not all that many squared-circle postmarks that could fit. It looks like it has to end in R A, or R A __?

[courtesy of clivel's ImageSleuth]
MADURA AND MAHOMMERA seem to be too short and too long, respectively. MASHRAK? MATHERAN? MAYAVARAM? If there is a letter after the R A, then there might be something before the M, or it wouldn't be centered at the top of the arc.
After I hit "Preview" I now think I might see something in front of the M and something else after the A. Anyone recognize a possible fit for the postmark?
How's that for a wild goose chase?