This was running slow for some reason (losing about an hour every couple of days). Have taken it fully apart, cleaned it (although it was clean anyway) and reassembled.
Seems to be working fine now... put battery in and left in the cupboard for a couple of months. Just taken it out and it's still showing the exact correct time.
There was some glue stretched across a small circuit board that I've cleaned off - perhaps this was the problem (?) although I don't know why.

Perhaps someone would like it to give it a go, and if it plays up again then it can go in the bin. Hopefully it will be fine, although I don't know.

It has an electronic alarm (hammer and bells are decoration) and is a ticking clock (vs a sweeping one). Hologram picture on clock face. Cosmetically in excellent condition.

New AA battery comes with it.

Collection Chellaston (near Snelsmoor Lane)

Marvel Avengers alarm clock (DE73)