The 105mm is mounted on the smallest mount??? It looks like they may not be for an Omega. The lenses are either mounted backward, or the mounts are acting to recess the lenses into some type of reproduction machine. To me, it looks more like the lenses are mounted backward. I also note that the lenses have a "P" designation next to the name. The aperture on the lenses is also fixed with a small hex head bolt. There is also a little dash printed on the aperture scale between f/11 and f/16, just where the lens aperture is fixed. I assume it will be free to move if I remove the bolt. The closer I look the greater the mystery becomes....