Gauge ID

Hi again

I went to a collectables auction today and scored a few things – one among them has me stumped. Following info on it

Gyro
code V 951
For GM2 Compass System
Kelvin & Hughes
Made in GB

It has an RAAF part number of G6B/500929 painted on it with a date stamp of 4 Feb 1953

The stamp that is most intriguing though is one that says A42-520 . Is this the aircraft number? If so thats odd as the only A42 I can find reference to is the Lockheed Vega, and I believe there was only one (A42-1)

Anyone have any ideas as to what aircraft it is from?

Thanks in advance