this is a S&G 3 disc lock. It looks pretty hard to pick but already I can feel the click for the first 2 discs just by rotating them with a normal tensioner.
I've been very curious about these locks, it's a pity the railroad collectors go after them too. I'd like to see some pictures if you ever disassemble it.
I do have one question on this. How is it diasssembled? I know the plug at the top has to be removed but there is a pin blocking it. Is there a way to het the pin out without destroying the lock?
If it's only 3 discs, it should be relatively easy to pick with an Abus type pick. Drilling it sounds a bit extreme - it looks like a really nice lock!