I noted Sheldon Banoff's cataloguing of town anniversary medals and the fact that Wendell's of Minneapolis was a prime maker of them. Earlier this year, I was researching a 1972 medal which commemorated the 175th anniversary of the incorporation of the City of Baltimore and the 175th anniversary of the launching of the U. S. F. Constellation. This is not the U. S. Mint medal which was also made in 1972.
I sent a friendly email to the president of Wendell's asking about any information they might have about the medal after being referred to them by someone involved with selling custom made medals around that time. In my email, I mentioned that any information provided would be credited to Wendell's.
I did not receive any reply to my request. My article was forwarded to the Editor of the Maryland Token and Medal Society Journal with the information I found and included my request to Wendell's which resulted in no response.
Perhaps I am a bit old-fashioned, but if I ran a company which deals/dealt with medal sellers and collectors, I would respond, even if it was that I didn't have any information.
I'm sure all numismatic researchers have run into such unfortunate dead ends. Other stories and comments on the topic of courtesy in research are welcomed.