This is a very nice K&E Surveyor's Transit. It seems somewhat rare because the serial # doesn't fit with the standard K&E serial # system. You will also notice on the compass "K&E Doric". Most K&Es do not have "Doric" with the name. I have researched this and cannot solve the puzzle (yet). The transit is absolutely lovely. It is from the late 1940's to early 1950's because it has a wood case, but the transit is attached to a metal base. Most transits older than 1945 were attached to a wood base. The optics are fine, and all movements seem to work well. The original wood case has 1 foot pad missing. SOLD AS IS! No refunds or returns!