Taken the wrong side of the light but taken with a particular thought in mind, 800007 and 800015 passes through Severn Tunnel Junction with the 1B35 12.45 Paddington to Swansea service. This very 'fussy' view contrasts with a photograph that I took of an HST in a very similar spot back in 1977, see....
https://www.ontheupfast.com/v/photos/21936chg/23615758404/my-friend-spotting-companion-richard. However, I think that the older picture was taken on the island platform to the right of me in this image, the new platform three.