29020-412, 571, Kollsman Aircraft Encoding Altimeter Indicator

3 1/8" Kollsman Encoding Altimeter Indicator as shown on photos. P/N 29020-412 or 571. 28V. Condition unknown. It appears that a small screw is loose inside indicator. Also, needle does not move when barometric pressure knob is moved. Sold as a core only or for parts, as is, no returns will be accepted.