I have just read a letter ending in the phrase "Yours in Perry's". May I know its etymology. Usually, I know of "very truly yours" or "sincerely yours". But the phrase "Yours in Perry's" is something out of the ordinary.
It is out of the ordinary- there is probably something in the context of the letter or the relationship between the people communicating that would explain it- it's not a standard ending or one that I have ever seen. Perry is a drink made from pears, but that wouldn't explain the apostrophe, and it could be a name of a person or place.