RFC aircraft compass cover?

[lucycutler]

Not sure if this is the right part of the Forum or not but here goes!

I found this canvas item at a boot fair a couple of years ago.  The vendor thought that it was a  cover for an aircraft compass.  As it was only £3 and was marked Royal Flying Corps, I bought it.  It's made of a lightweight cotton material, is 8" wide x 9" long x 5" high, and has a draw-tape along the bottom so that it can be closed up tight over whatever object it was designed for.  It has a rather faded stamp on one side which I believe reads:-

No...........................

SQUADRON

Ref No....................

ROYAL FLYING CORPS 

 

Any ideas Guys?  Is it an aircraft compass cover? Or if not, any ideas as to what it actually is?

Lucy