I've seem chains on Heinnie Hayes for around £10.
http://www.heinnie.com/Accessories/C...s/c-1-718-719/
but they aren't Pewter.
And there is a £2 postage charge now for orders below £30.
I prefer to use paracord, or 3mm soft rope for a lanyard.
The chains will scratch the metal work and the acrylic crystal.