Lost cat Warham/Seymour: The cat comes back. Darwin has returned

I'm looking after Darwin for Jo at the moment and we haven't seen him for about 24 hours. We live in Warham Road near the Passage and his usual territory is the back gardens nearest to us  between Warham and Seymour near the Harringay Passage. 

It is highly unusual for him to be gone so long and not to come when called as he's usually within earshot of his feeding bowl. He's quite a shy cat and very gentle so he could have squeezed in somewhere after getting a bit scared and got stuck. He doesn't have a big meow so you may not hear him if he is trying to get out of somewhere.

He's a big grey and white cat, wearing a collar with a bell and a little toggle thing that has my phone number inside it. He may have got in somewhere and got stuck so please could you check sheds or anywhere that a cat might squeeze into. He's missed a couple of feeds so is likely to be quite hungry. Please could you contact me immediately via this post or PM for my phone number if you spot him.