Update: the cat has reappeared in our garden, so he's no longer missing. But he won't come indoors yet, and it may be some time before he's willing to do so.
Any reports of sighting are still welcome - he's wearing the remains of the collar around…
Thanks for posting NoOne, but it doesn't sound like Blitzen - he's a boy (originally at least), and has only been missing for a few days. But thanks for thinking of us.
Our neighbours used to have a little tabby, Peaches, with a red collar, but they said that she'd disappeared (from Albert Road). Are you sure it's a boy?