Sticking Mortise Lock - Install or Lockset

[pingable]

Been helping a family member out and had some issues with the lock.
I thought it may have been doublelocked from the inside and regrouped.

Made a call as I was not able to open it today as well, and it turns out the lock was finicky.
Long and short of it, I had to turn the cylinder and just *flip left and right slightly* till it releasesd the latch in the mortise lockset.

Upon getting the door open, the bottom screw that holds the lockset body to the door was loose. I screwed it in tight and plan to bring some Loctite to the threads.

Anyhow for all you fine gurus out there, was it just a matter of the screw holding the lockset that was the issue or possibly because it's a 50 year old mortise lockset that the guts are loose ?

There is a medeco cylinder in it, and my issue was was that the 1st turn to the left unlocks the deadbolt. The second turn to the left opens the *latch* the allows you to turn the left. The turning and the latch not allowing the know to turn was the issue

[Greasemagnet]

I would recommend removing the medeco cyl. and spray lube into the lock,DO NOT use wd-40, use something like tri-flow or something like it.