Issues with my Tele-Sandmar 100mm for an Argus C3

[Dr_Totenkopf]

OK guys I got a telephoto lens for my Argus C3. I put a roll of film through it and I have massive distortion in the center of the photos. Am I just using it wrong? On further inspection I noticed that there is a small amber lens in the center of the focusing lens. I have no clue if its suposed to be there. Any one familiar with the lenses let me know.

 

[compur]

Open the aperture fully and look through the lens while shining a light through the other end. This will make any internal marks, fungus, debris, etc very visible.