Thanks guys - they are tiny, very very tiny diamonds, but one of the on-line diamond valuing websites valued it at £1,000,000. That would have been nice!
I think that if the set is worth £50 I will be very lucky.
You could give it a try on Ebay - 2 separate items would improve the chances - check out the going prices, and set a sensible opening price. Good luck!
Better yet, for your first try, don't use the Auction[i mode but go to the [Fixed Price] tab. That way you can set your own price to see if you get any response. You could also set a minimum price in the Auction section, but I find that usually turns people off... at least here in the U.S.