this model does, indeed, as others said, look like the popular IVSB, but it also looks a lot like a couple of other models pictured by Dechert in his Canon book -- particularly the IIF, which Dechert calls "the PX camera" because most were sold through PX's with the red EP [exchange post] designation...The serial number on your camera, however, is very early...
If it is a IIF, the model name will be found on some IIF's on the inside bottom plate after you remove the base plate, according to Dechert.
regards, bob