Ole Hoerning

I´ve got a SOM Berthiot ZOOM M 20-100mm 2,1. It used to be mounted on a cine-x-ray camera, so it has the focus fixed at 12 feets. Does anyone knows how and where to loosen the focus? It has a C-mount, where there is printed "17-85/1:1.8" Does those values complies when mounted on 16mm film camera and or old school 1 inch tube videocamera? (I'm not cinematographer...only still photographer) And finally, is it possible to mount some sort of tripod collar on the beast?