So I couldn't find out any more about these jetons - the chips are staying with me though - so I have listed them on Ebay along with a few other UK and US chips and jetons.

Thanks for looking

Jason

http://www.ebay.com/sch/chipperuk/m.html?item=152415385999&ssPageName=STRK%3AMESELX%3AIT&rt=nc&_trksid=p2047675.l2562