Hey all, just looking for some help identifying this Rolleicord that I recently acquired. The serial # is 1039539, which leads me to believe that this is model IIc. But, the shutter speed goes up to 500, instead of 300, which is listed for the model. Also, I was wondering about what seems to be a second shutter release lever, next to the regular shutter release lever. Also there is a knurled knob on the front up towards the viewing lens, that I don't see in other pictures of this model. Just wondering what I have here. Any help will be appreciated. Thanks