Right, the General Aviation / Fokker PJ-1.
http://www.uscg.mil/hq/g-cp/history/...n_Article.html
I gather that General Motors, seeing Ford's success with the Tin Goose, had to have their own aircraft company. They arranged to gain control of Fokker (America) and rename it General Aviation.
General Motors - General Aviation see?
For quite a while I'd thought that the pic was of a Douglas Dolphin. I did some more searching before posting and turned up the fact that it was a PJ-1. It cartainly looks as though the Douglas Dolphin was closely related. Did General Aviation shut down and Douglas take over building PJ-2s (tractor engines) as the Sinbad/Dolphin? Even the wing float attachments look similar to me.
SC