Can I ask what the differences are in the CWN between eg PMV (4) and PMV (News)?
Can't say for certain, but I can make an educated guess based on very limited documents I have. The (4) I believe referred to the standard 4 wheel (ex SR) PMV's that were pretty common place. The PMV/News variant may have been similar such van(s) specifically allocated for Newspaper train diagrams perhaps, but I think it more likely, given the previous specific reference to (4) against most PMV's, that these 'PMV/News' vans were former B (bogie brake) vans. Most of these lost their brake status in later years I believe, and are classified in the CWN Appendix (1973 in this case) under the heading '
Parcels and
Miscellaneous
Vans (Former Brake Vans) Bogie' (without gangways)(B)'. Although B vans in their own right are still referred to in the CWN during the same period(s), presumably from the minority of those still in their original configuration perhaps?
The BY vans had a brake van and a stove, so might have made an alternative, if harder riding location for the guard, if the other heated vans were given over to Newspaper packers etc., and a small number of BY's plus a small number of 4 wheel PMV's also had chains fitted for the transport of BRUTE trolleys, but these (chain fitted) vans seem to have been concentrated latterly on the SED.
Afterthought: looking again at the 1963 entry for the 1.15 a.m. to Ilfracombe, I see B vans specified as 'News' vans also, so may be the PMV (News) vans were just 4 wheel vans allocated to Newspaper duties afterall?