So what would the Night Riveria formation have been in 1987? This was just before sector codes came so the Mk 3A Sleepers were still based at Wembley, possibly common user with the West Coast ones.
The 1987 Platform 5 Combined Edition shows all Sleepers based at BN or WB, bar a handful at EC.
The 1988 Platform 5 Combined Edition still shows all Sleepers based at BN, WB or EC but of the WB ones 11 are in pool IWRX (InterCity Great Western):
- SLEP - 10533, 10552, 10558, 10584, 10588, 10594, 10595 and 10601
- SLE - 10658, 10686 and 10720
All are Blue/Grey, apart from 10594 and 10720, which are shown as InterCity Executive.
Interestingly the 1988 volume has a picture of SLEP 10542 in InterCity Executive livery passing through Acton in an ECS formation on 24/04/87. Not sure when in 1987 the sector codes came in but according to the book 10542 is allocated to IWCX for West Coast.
At least it gives the option of including a couple of InterCity Executive Sleepers into an otherwise Blue/Grey formation if that's one of the services to model.
Also, 1987 is when most of the Motorail GUVs were renumbered by InterCity into the 961xx series. 96185 (ex 93083), 96186 (ex 93087) and 96190 (ex 93448) are all in pool IWRX allocated to OM and carrying Blue/Grey. They are also shown as being NXX. So again, you could model them as the Motorail GUVs in the 93xxx series as part of the Newspaper train mentioned up thread, or numbered in the 961xx series - not sure if sectorisation saw the Motorail Vans being switched to be in the Sleeper.
Just checked the 1989 Combined Volume and that has a picture of 96185 between a Newspaper Packing Van (94000-94034 series) and a 95xxx series Newspaper NC, both in Blue, with the Motorail Van in very weathered Blue/Grey - but the train is at Newport, dated April 1988!