Were they Wimbledon-allocated EPBs or Selhurst-allocated?
Selhurst. Anything using platforms 9 & 10 at Wimbledon (as was) in normal service was Central Division.
It was something to do with the funding available at the time; I've seen the full story elsewhere on the forum somewhere a few years ago - I'm sure it could be found with a bit of searching. It was quite interesting.
May have seen the same thing, and got the impression the 508's were initially ordered for Merseyside, but got diverted to SR/SWD? This was (is) new to me, as being on the ground at the time we received them on the SWD, they were just the first of 'our' new trains, so thought no more about any politics that may have been going on at senior levels.
With regard Windsor HC's, 18/58, the answers above I would think are all relevant (neither wrong nor right, or should that be 'all correct, for the timetable period they applied to'), as the timetable and service patterns changed throughout these years, as did HC's.
I don't have the minutia detail, but just to say I posted an image above showing an ex Tyneside 2 EPB on an Up Windsor (HC 58) awaiting the Weybridge portion to attach on rear at Staines. That was taken October 1981. I have another image I took at Waterloo in October 1991, almost ten years to the day, of an 8 VEP departing Waterloo for Windsor on an additional service icw Twickenham Rugby displaying HC 18.
Can not remember when the Windsor/Weybridge splitters were taken out the plan, but do recall the discussions around same, as they were considered a risk to the overall Windsor line service as they relied upon every crew member being in the correct place for every such detachment (to do the physical detach and work the Weybridge portion). It would only take one member of crew to not be there for any reason, and the line could be subject to delays, at a location that was/is, as many will know, extremely busy train throughput wise.
Other workings of the unit include
0730 Guildford - Waterloo via Ascot (with a CIG)
0942 Waterloo-Windsor (with a CIG)
Divided at Windsor
and then
1458 Waterloo-Reading
1632 Reading-Waterloo
1805 Waterloo-Guildford via Ascot
(all 3 with a VEP)
This was 1982 only, not 1981.
Were CWN amendments common incidentally?
Further edit:
In answer to your last point here. Apart from the main TT change dates, May and December, there were PA (Permanent Alteration) dates. These dates could be applied to start at eight weekly intervals, and were governed by certain Train Crew rulings. Too many such issues on a consecutive basis, or too many changes to the plan in any one issue, would likely be rebuffed by Train crew side, in which case any alterations would have to be delayed until the next major TT change. But provided changes were acceptable to all parties, a PA notice would be issued, which took pressure off the STP planners having to reissue all such alterations every week, whilst still having the changes in place on the ground, which would then form the basis of the next major TT change.
As for the 2 car diagram above. The nearest CWN I have is 1979 so there have been changes, stock and timings;
I had assumed the detach was at Waterloo, but not so. This may say more about the CIG diagram, than the HAP?
So the HAP worked solo on the 10.44 Windsor to Waterloo/11.42 Waterloo to Windsor and 12.44 Windsor to Waterloo, due 13.32. Did it then stay on the blocks at Waterloo to await the VEP forming the front portion of the 1458 to Reading? What are the times/origin of that inbound VEP?
Also, what was the next move of the CIG left at Windsor?