Thanks for the responses. It's nice to see a consensus as it gives me confidence with what to do next. I noted also the dirty read on the timegrapher as @clockboy pointed out and will see if I can clean that up a bit.
Apologies for not responding earlier- my wife's Mini Cooper blew up and the repair has kept me quite busy and away from the desk!
Well done wls1971, it was made in Japan. I did not repair it as it was easier to make the inside of the case fit a new German Regular movement that is of a bit better quality. Also added 2 new bellows as the originals had high pitch cuckoo and sounded terrible.
Yes, yes in order to remove the top screw I had to release that level what you use to stop the alarm and the stop button too. Actually the top screw goes trough the outer case and the inside frame. The inside frame was also bent, so it was actually enough to put the top screw in and tighten it to stop the clock. I straightened up the bent and now the top screw is not an issue anymore. Hopefully I can sort this out, thanks for both of your comments.