This truly unique lens is labeled "Objective for Askania Theodolite, Goerz Optical Co., 1967". It's a very well-built, solid, short, open OTA with all the corrector lenses inside the central baffle tube. All the structural components and optical surfaces appear to be in fine condition. I believe it was used for very accurate metric photography by the DOD, and as such has these characteristics: top-notch baffling, complete even coverage of at least a FULL 35mm film frame with minimal aberrations, highly stable tube assembly both thermally & mechanically. Probably cost thousands of dollars originally, and the Goerz name means top-quality optics. It certainly ain't no Meade!
The back of the OTA is open in the sense that it was meant to be mounted on a strong flat surface, coupled by means of a short 6" bellows/adapter thru a central opening to the film camera directly behind. Focusing can be done internally by means of a numerical-readout dial that moves the final lens assembly back & forth via a circular worm gear. Or you do it externally. I have no means to mount this lens, so I tried to evaluate image quality subjectively on terrestrial objects using temporarily mounted eyepieces and a few pix with a Canon AE-1. All the images I viewed appeared to be high quality, as least as good as the images from my other telescope optics - excellent contrast and consistency across the field.
Some basic specs - OTA diameter 13.6", length 19.6", weight 30 lbs. A snug front cover is included. The pictures try to show everything. I'll try to answer any questions -- more pictures are available for emailing.
If you don't like its images, send it back (you pay all shipping & insurance costs). I'm asking $890 plus shipping/insurance ($30-$50) OR best offer. I've just got too much stuff and something has to go. Why not consider owning a truly unique optic, something different than all the Meades and Celestrons out there?