Mosler 301-401 and 302-402 UL Group 1R Combination Pix
Specifically I scored a couple of Mosler locks in an Auction a while back that took forever to arrive.
Below, for your viewing pleasure is a teardown as far as I was willing to go with it. Which, as it turns out, is not too far. Neither appear to have a regular spline key. I gave what looks to be a (double) spline key interfacing with the central shaft/bolt a pretty solid tug with a pair of pliers and that didn't seem to do me any favours at all besides messing up the brass finish sadly (on the 302-402). The 301-401 appears to have a threaded insert so I'll give that a proper try a bit later too when it comes time to mount it.
Any suggestions on how to dismantle this further would be most welcome. The wheels themselves would be possible to take apart further and if there's significant interest, I might give it a shot (I can see the circlips, but I can already tell they'll be a pain to remove).
They are a very unusual lock design (to me) and the first Mosler locks in my collection.
I'm not sure if the design is standard for them or if the choices here are specific to the group 1/1R locks they produce but some very cool anti-manipulation features as you'll see below!