Difficulties with wearing a device? discussion

I’m using a gadget with an inertable brass barrel. The key turns the pin at the end to the right, which lets me pull it out—it’s the same locking mechanism as in the HT2 model. However, that end pin won’t rotate back into alignment with the rest of the brass ridge so I can remove it. And before too many suppressed giggles break out: yes, I was testing these locks while wearing nothing else! Fortunately!

Does anyone have ideas on how to resolve this? If I manage to get it out, I’ve got a spare lock or two lying around. I’ve already tried lubricating oil. The pin does turn but stops about 2 or 3 mm short of being aligned. Are there any locksmiths or engineers here?

If someone just tells me the proper name for this kind of lock, I can look it up myself, though finding videos or instructions has been tricky without knowing that corect term. Please help!