Obo, According to a quick trawl on the web: there is a Grimsby in Canada (in the County of Lincoln, so I assume that at least one of the folks who named it knew of Great Grimsby, Lincs.) near Niagara. That's it. I am frankly appalled. For a town which has had its charter since 1100 and odd, you would have thought it would have spawned more namesakes. Anyhow, what's wrong with the name of Grimsby? Better than 'Fishton upon Humber' which was one of the recommendations made when NE Lincs was set up!
Andy