Sometimes you acquire some bizarre, crazy things, and here is one from my postal history collection, with contents, front and back, postmarked June 10, 1911 from Newark, New Jersey, USA. I think it was a stamp dealer talking to another stamp dealer about acquiring sets of stamps and their prices. What do you think?
The envelope is postal stationery from India - Gwalior State measuring 4.5 inches by 2.5 inches, but it was mailed in Newark, New Jersey, USA with 2 cents US postage applied. It did not originate in India. The enclosure is a chopped postal card from some country, I am not sure.
People back then had a sense of humor just like we do. It's wonderful to see it come through in some old object like these because we tend to think of them as serious, not funny. You're lucky to have that interesting cover.