Hainault loop to get re zoned 5 to 4

I can see someone trying a revised route for the tube challenge now that the eastern end of the Central Line can be done at the end. It's one of the few long spurs without a realistic alternative to get back to the centre again quickly. For example you can get back from Upminster using C2C in a fraction of the time taken by going back on the District.

A change to the tube map will be necessary, how much money will be spent exactly?

I've got an old electronic copy somewhere, possibly from around 1997, that has no zone D and the key still makes reference to the possibility of Central Line stations beyond Z6, although Ongar, etc were already no more.

Watford Met was in Zone A at least as far back as June 2005 (the oldest map I have readily to hand)

I've found a map shown as version "04.03", which I believe translates to April 2003, which shows it in Zone B. By version "1.05" (January 2005) of the London Connections map it is in Zone A.

I've also found a zones map "(C) London Regional Transport" with no obvious version number but a file modification date on my system as 03 March 1998, the JLE was still under construction the DLR extensions to Lewisham and King George V weren't shown as even proposed. Mornington Crescent was closed for rebuilding.
Zones 1 to 6 are shown in different colours (1= white, 2 = green, 3 = yellow, 4 = salmon, 5 = blue, 6 = pink) with a thin white line between them, but Zones A, B and C were shown as one group on a white background. Stations in these zones had §A, §B or §C as appropriate in red after the station name.
Stations in Zones 1 and 2 had green and white hatching, other stations in two zones had a white box. Moor Park is not shown as being in Zone 6 and Zone A but the symbol is placed on the line dividing the two zones. Similarly Epping is shown on the border of zone 6 and being beyond the zones, although there is no line to Ongar. Upminster by contrast is placed wholly within zone 6

The key for the zones shows the stations beyond the zones as a table:


The diagram of stations in zones also uses the red of Central Line rather than today's maps that use the Met Line colour. The key diagram suggests that stations in more than one zone can only occur between 1 & 2 and 3 & 4, despite other combinations appearing on the map - e.g. South Wimbledon in zones 5 and 6.

I would simply upload a copy but I know that the powers that be are happy to have really old maps around the net, but are less than keen on modern ones. If someone knows the score let me know.

Well, obviously keep well away from these stations for fear of being crushed in the stampede of new passengers.