Spanky, there may have well been 2 different 707 engines. The 707 of the 30's didn't resemble at all the other engines in the series you mention. That whole series of engines is pretty obscure because they were in heavy trucks that were run into the ground and scrapped. Smaller trucks were used by farmers and a lot of them spent most of in barns. I just don't have much information on the earlier big trucks and I don't know of anyone who does.
