Group 1 Yale??
When it arrived, I went straight to working the lock. How many wheels, pickup differences, and contact point(s). The first thing I noticed was clicking/ratcheting, much more so than just gears meshing on an indirect drive dial. In fact, there are 100 clicks all the way around one spin of the dial when turned slowly and carefully counted. What the heck?! A lock just like in the movies? I couldn't find any definite contact point, and I wasn't even really sure the number of wheels. This may not be do-able after all!
Since the top and bottom of the box have coin slots, and the rear corners have mounting holes, I was bale to spy inside with illumination, and this is what I saw.....
A rear cover having a raised disc offset toward a corner.
Yale Made in USA
Warning! Turn dial to 50 before removing cover.
UL Inspected Combination Lock Group 1 No.197044
Group 1! I didn't know of any Yale Group 1s, and this lock is in none of my references. This little box has government written all over it (figure of speech). Heavy duty construction. Hints of zinc oxide or zinc chromate primer under the Navy gray paint. And, now, a Group 1 lock.
What do I have here? What is this lock? Is it rare? I plan to drill a couple holes in the back to work the cover off and manipulate the wheels to an opening...when I can get around to doing a proper job of it.