Cufflinks

[Smylers]

A friend has requested cufflinks for Christmas, silver (presumably she
means silvery-coloured, rather than made from silver).

Can anybody suggest where to buy these?  Preferably in Zone 1 and open
after work tomorrow (I'll be arriving at Paddington and travelling to
the pub meeting near Euston, via a cufflink vendor).

Oh, and if I end up somewhere which has a choice of silver cufflinks on
sale, any advice on discerning which are the 'nicest' would also come in
handy!

Thanks.

Smylers