My 11/44 uses a barrel key (which now that you mention
it ISTR is plastic),=
but this is a flat key. =20
So presumably it's a a 'Yale type' key (as they're commonly called over
here). A flat key with notches along the top edge to lift the tumblers to
the right height.
I can't believe it's a very complicated or secure lock (cheap locks, with
looser mechanical tolerances are much easier to pick for obvious
reasons). My guess is you could easliy learn to pick it. And once you've
got it open, take the lcok apart and you could probably make a key.
I assuem there's mo other way into the cabinet. One of my machines had
the back cover held on by a lock for which I didn't ahve the key, but
turning the machine on its side revealed 2 metal plates that the rear
cover hookded on to. Unscrewing those alooed me to remvoe the cover
without the key, at which point it ws trivial to dismantle the lock to
make a key.
-tony