Need Help with a Seeburg STD160

My fiancee has one of these jukeboxes, and we were trying to open the
top to tighten a couple screws on the bar in the front (where the
titles are held).

What had been happening was that to open it you had to keep pressure
on the key on the left in order to have it open the latch on the bar.
Well, after futzing with it some, the end of the lock came out
attached to the key. Now, we can't get the top open.

Is there a way to open the top without the key? If so, how? I don't
have a schematic, and am not really sure what I need to trip in order
to be able to open it. I was only able to open it one time before,
and that was to find and tighten a screw in the cabinet.

How can the cabinet be opened without the key? What I see when I
look thru the keyhole at the left hand side of the jukebox, is a
slanted piece of metal, probably about at a 45 degree angle. What I
see is the "bottom" edge of it. It covers about a third or a little
more of the keyhole, from about 1 o'clock to about 8:30. I can see
the rod running all the way across, and I can see the little triangle
on the latch on the other side.

Help!!!!!!!