Hi, folks. I tried searching for this, but as I am still learning all the proper terminology I may have missed previous threads. That said, please excuse my ignorance. I've just been gifted an old Speed Graphic (still trying to determine what model it is, but the serial is 447446) along with a Polaroid Land Camera back for it. Everything seems to make sense, but I'm trying to figure out if there's a piece missing. When I look through the shade and ground glass, I only see inside the camera body (for example, I see the darkness of the bellows and the lens itself, not the image that I should be seeing). Is there a piece missing that goes in between the ground glass and the camera body? Thanks in advance for any help!