David
Why didn't I spot that! I've had a bit of a dismantle and found there is a laser pointer down the middle, obviously replacing whatever was there before, and the level on top is diffenent as well, but I'd still like to know what it was before it was modified, the rack and pinion thing would seem to be of little use in any long range instrument, but then the bottom bit with the 360 degree protractordoen't look like it was originally part of the top bit, the paint is completely different. Perhaps it's the ultimate bitza, a microscope body mounted on an old theodolite base?