Here are my three candidates for this thread.
This one I picked up on ebay for 99p and it turned out to be hallmarked silver:
This one I got free with a credit card many years ago. I broke the strap's spring pin recently so decided to treat it to a new strap for all of £6.50 from China.
And this one I was left by my Grandad when he passed away. I think my Mum and Dad bought it for him when his eyesight was fading about 30 years ago, so they wanted one with large numbers. It's a hand-wound Longines, but I don't know anything about it apart from that.