Looks good to me. Welsh-made I think, rather than the higher-grade Cheltenham models (which say "Made in England" rather than "Britain"). Does it tick loudly? That would indicate a low-jewel pin-pallet ecsapement. Was it issued by the Coal Board? Some have markings on the back that show they were.
That would look great on a chain with a waistcoat.
Enjoy!
PS date: I think 1950s. I'll have a look later.