disassembling hatch lock cylinder on an XJ?

Nope, that's not the lock assembly either. I've taken my share of them
apart before but mostly door or ignition types. That one turns the
bell crank. This one is the typical XJ hatch lock, it's the
push-button trunk style. It doesn't appear to have an obvious way to
remove the cylinder. No circlip, drift pin or the usual tricks seen on
most lock assemblies. I'll try and post a picture of it tomorrow.

As for oil, this wasn't the lock cylinder that lacked lube. It was the
striker/catch assembly. Dry as a bone but I suppose that's to be
expected. I'm well aware of not using oils in lock cylinders.
If/when I get the actual cylinder out of the assembly I'm prepared for
the usual leaping spring risks. I only want to extract the broken tip
of the old key from the cylinder. It's too far in there to extract.
Made even harder due to the the spring-loaded cover inside the keyhole.
Yes, I could pay a locksmith to do this but that'd probably end up
being more than this old wreck is worth.