George Dettmer and Son

[Ampicoman]

I have come across a George Dettmer and son with the upper Mary le bone name on the fall board. It is an upright piano which seems unusual since most pianos from that era were square grands. Would it be similar to a fortepiano?? Have you heard of this maker making upright pianos??

Dave Goodwin

[Bill Kibby]

Firstly, you don't say what era? Square grands were an American thing, the English and European square pianos were often smaller, lighter and cheaper for ordinary homes. Dettmer was at Upper Marylebone Stret (Mary-Le-Bone Street) from about 1808. English square pianos were dying out in the 1860s, but the American version survived until at least 1899, when Chickering was still making them.
Are you able to show us photos of the whole piano?