Ok, so I did manage to get it apart. Both retainers have to come off, but the crimps were fairly easy to break and scrape away. Then the core can come out like you said. Here's a few quick and dirty pics (I've still got a bunch of work to do tonight and this was a fun distraction, but need to get back to it)...
Here's the lock mostly broken down:
at the top, from left to right, is the main spring which sets into a hole in the brass ring on the back end of the core (that ring also has a slot cut in it that limits rotation) and a hole in the back of the body. The smaller spring puts pressure on the actuator, the little white piece... it has recesses that let a little microswitch button sit in it and pushes the button when it's turned. The two retaining clips are next, which fit into the bigger grove near the rear of the core. They each have two notches where the body is crimped to hold it in. And the brass pin cap.
The core is similar to Oldfast's but longer... typical medico slotted pin chambers, and you can see the sidebar at the bottom. I didn't take the sidebar off because it is also crimped in place.
Closeup of the pins and springs:
Another difference to Oldfast's lock is there is only a single false gate groove on each pin. The hole is where the fingers of the sidebar fit when it's lifted/turned properly. The little stud on top fits into end of the spring.
Another shot showing the sidebar:
Taking it apart wasn't so bad, but putting it back together was the real treat... Interestingly (sorry didn't get a pic of this) there are three sidebar grooves in the body. It can be changed from clockwise to counter-clockwise by putting the brass ring on differently and using a different groove... accidentally did that first. Really wish I had marked it so I knew which way was up... took a good bit of trial/error to get it back in, hook the main spring and seat it all the way. Be prepared if you decide to gut one of these. I really don't think they mean for these to be serviced, tho it wouldn't be an awful job to rekey one with a little practice.
Pretty cool lock, and I think I have a little better idea now how to pick it. I had imagined it slightly differently... and knowing is half the battle
Hope this helps you, too, Turtle0Monkey... let us know if you get it picked!