I've had no luck (yet) in obtaining an earlier edition of the NLC directory, however as an aside have been looking at pre-NLC codings used, in particular on the LM region and am interested if any listings exist in respect of these codes.
Apart from on the Southern and Western regions, station of origin coding generally only appeared on Edmondson and Ultimatic tickets issued at other than "home" stations.
These fell into one of three camps...
(1) Excess tickets from small stations, often only staffed during morning peak only (eg: "Denham Golf Club 3051", issued at Gerrards Cross) NLC for Denham Golf Club is 3060. On Southern, both Canterbury stations and Ashford Kent carried a large range of such examples.
(2) Tickets for national journeys issued at suburban stations, eg: "Glasgow 9681 to blank" issued at Greenock Central
(3) On Merseyrail, as opposed to issuing conventional "return" tickets, two individual tickets were issued, the return coupon always reading from "Liverpool nnnn" where nnnn = the NLC of the issuing station. (eg: "Liverpool 2201 to West Kirby" - issued at West Kirby 2201)
In the above examples, the station of origin is easy to identify as the tickets carry an NLC. However, without a very old code listing, others aren't. For example:
Coventry 26352
Birmingham 26468
Frankton Halt 65763
Liverpool Lime Street 23412
Liverpool Lime Street 23431
Manchester 22667
Manchester 22704
Blank 27154 - although I happen to know this pre-NLC code was for Wembley Central 1423, as was on site in 1987/8 on the day the stock was withdrawn & Aptis installed.
If anyone has any further detail or listings of these old coding schemes, please come forward!