I found a single key on a key ring with a whistle and an entry fob.
(Bob on 22 Sept 2022)
When: 11 Nov 2019
Where: Queens town road train station(51.4753° N, 0.1464° W)
I had taken a new Oyster card on 10th Nov 2019 and recharged with monthly season ticket from Zone 2-5 starting from 11th Nov 2019. I punched in Queens Town Road train station. I boarded the train after 4:30 PM to Hounslow. I am not sure if the card got lost in the Queens Town Road train station or in the train which I boarded for Hounslow. I searched for my card in Hounslow train station and didn't find it. If you find the card please call at +447404449145.
Could one of these be yours?