altimeter/inclinometer help

[CWccw]

I know this is an old thread, but if you need some photos let me know, I just repaired my inclinometer.

I just got one of these for my 3rd gen, mine is doing the exact same but I'm missing the 'lock' knob on that shaft. I can't rotate it by hand. All and any pictures you could supply would be great. Oh, save from archive bump!