The link in the note can be dismissed as untrustworthy, because although Valero is showing a Mile End map, its giving a Basingstoke address and a Reading postcode that's 76 Km away. 

https://pbfsltd.co.uk/grove-road-service-station seems to be the real website for the petrol station (and Texaco's marketing agent is also showing PBFS when searching for Texaco Mile End -- https://locations.valero.com/en-us/LocationDetails/Index/51-53-GROVE-ROAD/0000886409. So I'm sure that's the correct link for the petrol station. But I didn't check (beyond the street visible signage) whether the Spar shop is still open.

