Them were the days !
mikehallam (your #7903),
We used to line up on the runway for take-off, put its known magnetic heading on the Directional Gyro, and not bother about compasses or anything else. As our trips were never much more than an hour, it worked well enough (unless you threw it about a bit, and toppled the gyros, in which case you were back to square one).
In the same way, you zeroed the altimeter on the ground, and that was good enough locally until you got back. En route, of course, you'd work on the Regional QNH.
Life was simple in those days. Danny.