I've been using this Bruce Edward's mix recently, with good results. I discovered it, and indeed, Cr0; after 'googling' Bruce Edward's. I was a member of the Curry Club back in the 90s, when he published some stuff in the Curry Club mag. In one of his articles he mentioned three spices mixes that he thought BIRs might use, and I used his 'medium mixture' till I found his updated mix (the one containing curry powder) on Cr0.
In my first batch, I used curry powder by Schwartz, and result was OK. The Schwartz Curry powder was not at all like the stuff on sale years back which tended to be just yellow, with a smell of not much more than Tumeric. In my last batch, having read some contributions on Cr0, I used A Basaar mix (I used 'King of Spices' Kashmiri Basaar and I could not get hold of the recommended '5 Star' or 'East End' stuff. In found it in one of the Indian Grocer's shops in Crawley. This Basaar smells very nice, and in it I can detect the aromers of Fengreek, corriander and Turmeric. It does not have a list of ingredients, but mixed-up as per Bruce Edward's instructions it produces a very good result!