I thought I'd spend a few minutes writing out what "I think" I found out about these two in hopes that it will save future searchers some time.
First off I am trying to restore our 54 Flying Cloud to some sense of originality. At some point it was converted to a door knob complete with the nice square patch that went with the modification. Our goal is to return it to what it was. So the search begins ( btw I'm still looking).
First off there are two types of these openers. The L-54 and the L-55.
There is a big difference depending on which way your door opens.
L-54 If your door has the hinges on the right (looking at it from outside)and the door handle is on the left side of the door then you have a L-54
L-55 If you door has the hinges on the left and the handle is on the right ( which makes it the suicide door) then you have a L-55. They are not reversible or interchangeable.
Now then the outside bezel and the handle and lock assys. are interchangeable and will work on either lock assy.. That assy is known as H20-2. Both the lock assy and the handle bezel assy are extremely hard to find, I know I have been looking for a while now. Anyway at least I know what to look for now, and hopefully this helps others as well
BTW, anyone have a L-55 lock assy they are willing to part with?