Mike,
You might try a little Bernz-O-Matic heat on a glued lock. I haven't had to do this on any of our local locks, but it might work. Once you have the lock off, soaking it in a stripper might work.
You might also try welding the lock body vertically (key goes up) to the post, if that's what you've got. Anyone tries to shoot CyA uphill into a lock might find they got a fistful of cooked hand. They won't leave any fingerprints, though....
If they pour CyA down from the top, a sharp smack with the mini-sledge should pop it loose, especially if you have been dosing the lock with grease and WD-40 right along.
Dave