Can you help me?

That's immensely frustrating. British Rail(ways) used to produce an annual "system map", but the earliest I've been able to find is 1961. Here's an extract showing the density of branch lines pre-Beeching cuts (click to enlarge):

While that's obviously fascinating, I'd never before seen a pre-1959 version also showing the M&GN system in East Anglia -- until I caught this tiny, blurry image taken from a website advertising a book for sale:

Tiny and blurry it may be, but you can clearly see the M&GN mainline stretching across the top part of Norfolk. So here's the challenge: does anyone have a link to a decent image of this map, or an e-copy you can send to me?

All help gratefully received.

PS: And I have now received some help, very gratefully -- the 1956 British Railways Passenger network map:

One of the reasons the M&GN did not survive can be clearly seen on this map: the way the "mainline" is taken to start at Yarmouth while Norwich is served only by a branch. This insistence that the biggest population centre should be bypassed while a small fishing town and holiday resort was treated as the main destination has always struck me as wilfully perverse.