We spotted a concerned looking owner on our street as we arrived home from the kennel so we have now taken her to pick up Jason! Doggo and owner happily reunited. As you were!
If you haven't already, maybe check doglost.co.uk
Update - at the advice of out of hours council helpline we have taken him to Wearside Kennel where they will check if he is microchipped. They have our details and will keep us posted. We won't let anything nasty happen to the little fella.
I've shared this to the SE23.life Facebook page.
Thanks @BovillBunny Pleased the little chap is safely back with his owner. I have updated our social channels.