Thanks for your reply Mike. Sorry, my paper ticket from Swindon will be to a station beyond Paddington and probably Zones 1-2 (work is buying the ticket so I don’t know what exactly I’ll end up with). Thank you for confirming about Highbury & Islington. I’ve since found this video from September 2021 and it’s just about possible to see the Card Reader sign on the northern Victoria line platform.
[video subsequently deleted]