Kirks518 is on the right track, I reckon. All these cameras varied, sometimes even the same models indifferent factory releases changed the lockdown. Press down (gently!!) on the bars between the bellows, that may do it. Or look for a button - some folders have it in front of the lens on the front plate. As I said,they are unfortunately, all different.
Usually pressing on the bars will do the trick.
The keyword to remember is g-e-n-t-l-y. Don't force anything.
The camera looks good for its age. It looks like a 6x9, so you will get eight images to the 120 roll. Ideal for landscape work. With luck, open it and you may find a 6x45 insert still in the back, which will mean 16 shots to the roll. The Prontor shutter is excellent. Avoid changing speeds when the shutter is cocked.
Oh, and check the bellows for light leaks. Go into a dark room, open the camera back, turn off the light, and put a small flashlight into the camera. If there are leaks, you will likely see them. Fix them (see other threads about this) or have them fixed before you put any film thru the camera.
Enjoy!
