"I'd be happy to leave it with you for a small donation to help with the costs of the World Wide Education Work." If you heard that (and had never been a JW,) wouldn't you think #1: Selling, #2: Fundraising, #3: Raising money for school?
Sounds plausible to me that it was a JW. There is a branch in Puerto Rico, isn't there?- and certainly many congregations. A non-JW might not understand the distinction between KH, Branch, and Headquarters.