Working from photos I've created a panel for Mike Stone's Bristol 170. The autopilot in the photos appears to be the old Sperry unit and the only Sperry AP gauge I've found is:

SPERRY.MARKIII
SPERRY.PILOT.AP.SWITCH
SPERRY.PILOT.SERVO.SPEED2

(all files dated 8/98)

The problem I'm having is that, regardless of AP settings, the aircraft banks sharply to one side or the other immediately when the AP is engaged; to the extent that the wings are nearly vertical within five seconds. Is this old gauge just not compatible with FS9? or a problem with the air file? or something even simpler I've overlooked?

I've used many other FS98 gauges in FS9 with no apparent problems (mostly FSD, DFD, etc.).

I could transplant the DC3 AP, but it doesn't look like the Sperry in my photos.

The DC3 auto pilot is typical of the time and looks much the same as the one used in the panel made for my Bristol 170

You may be looking at a later more modern fit.

Which aircraft is your panel pic from??