Directional Gyro, RAF Mk IB, Ref 6A/1666 1945 NOS
This is an interesting WWII-era Directional Gyro, labeled for the British RAF as Gyro Mk IB, Stores Reference number 6A/1666, with a year of manufacture of 1945, and the late war Air Ministry upward arrow symbol on its data label, made by the US manufacturer Sperry in New York. It is new old stock, but out of its box. It is very similar to the US spec Directional Gyro AN-5735-2.
What makes it particularly interesting is the white anchor stamp for the US Navy. How that got on a British instrument, we may never know. However, aircraft of the US Navy were used by the British Royal Navy during WWII, such as the F4F Wildcat (as the Martlett), the F6F Hellcat, F4U Corsair, and the TBM Avenger (as the Tarpon). So it is possible that there is some connection there, but its pure speculation. It has the typical British warning usually placed on RAF gyro's "DO NOT JAR HANDLE LIKE EGGS".
It is in exceptional condition. The knob rotates the compass card when pushed in and turned, and frees the compass card when pulled out.