Thanks Silvercreek for your kind offer. As you say, shipping costs to Europe are excessive, mainly because they won't 'ship' by surface mail but insist on air-freight.
While looking at Killer Bugs I came across Tim Cammisa's version on youtube :- http://tinyurl.com/n76rvhv
As you see, he uses Jamieson Spindrift in oyster :- http://tinyurl.com/mglgprf
It's also a 2 ply wool as per Chadwicks and Borroco UAF. At this price I'll also get a match for the more yellowy sand, used on the bed of the local lake/reservoir. Could prove handy for bodies for other patterns.
I think the oyster will work better on the feeder streams.