If I could suggest a slight danger to your bank balance's safety, my 1952 ABC reprint shows 68899, 68905 and 68924 allocated to 32A Norwich (subsheds at Cromer, wells-next-the-sea, Swaffham and Dereham.) Not too far from Cambridge......
It's thin I know, but I've used it as an excuse to buy 68971 and renumber it to 68905 for my upcoming Wells-next-the-sea inspired layout, to go with the lovely new J15 and D16/3 that Hornby have also sprung on us recently...