http://www.125group.org.uk/wp-content/uploads/2018/07/HST-Diags-GWR.pdf Deceasing all the time as more IETs come into traffic
The only services stil pretty much all HST operated on GWR, are the South West services beyond Taunton, though a couple later this month are going over to 802’s.
GWR have one short set Here's a list of 2+8 diagrams which is better to understand https://www.railforums.co.uk/threads/remaining-gwr-hst-diagrams.164465/
The Summer Saturday Paignton diagram has gone to a 9 car 800. Everything else west of Taunton remains HST.