With the lens selected, the next step was to get the entire assembly into the camera head. You can see from these photos that the thickness of the assembly was quite a lot deeper than the original.

To make this work I was going to have to dremel out the metal body and mount the CCD board flush with the back, which gave me an extra bit of space. To get the lens to fit in the original housing, I used the plastic lens cap with the cover cut out; it served as a soft, perfectly sized gasket to hold the lens in place.