Right Iain, here we go.
Hook: Partridge 15BN Klinkhamer, size 16
Thread: ultrafine Wonderthread
Post: Grey calf, split and slightly tilted forward (as in the Goddard Emerger)
Hackle: Dun
Body: Uni-Floss, orange
Rib: Uni-French, gold, XS but for a more yellow/gold rib I use a thread from my local craftshop: Mettler Metallic No. 40
Thorax: Haretron Burnt Orange well picked out and tied in in a spinned loop
I suppose it's a general fly, but it's been very effective for me on The Don when there were Blue Wing Olives hatching. In our polders, rudd love this fly as well.
Look forward to your picture!
CU
Jeroen