I haven't been able to find out which model this is. The closet I have come is the Automat type 2 or 3. The serial number is 1038xxx but it's possible the hood has been swapped since the view finder only has a small magnifier as seen in the photos. Also there are two post which appear to resting spots for your thumb and forefinger and the lever near the bottom post will also trip the shutter.
The posts would hold a solenoid for flash. The lever with a pin sticking out between them is a shutter release that would be attached to the solenoid. You'll see modifications to this era Rolleiflexes all the time for flash and such. Lots of empty space inside these things for adding mounts, etc.!
Looks like a pre-war late model automat- bayonet mount on viewing lens but Zeiss lens and gray paint in shutter and aperture dials. One of the last models made before WWII shut down production, I assume. The magnifier is new to me- looks like a preliminary study for the later flip-up magnifiers. Maybe somebody else knows more details.
Yes, it's a late pre-war Rolleiflex Automat. The viewing hood probably comes from a Rolleicord Ia, type 3. The original viewfinder didn't have a sportsfinder like that, and the original owner probably wanted one so he could use the camera at eye level. Dan Daniel is correct about the solenoid.