I’m glad it was of some help! I wasn’t sure whether this was the fly you were looking for but, I had been tying some of these recently, and it twigged my memory. Sheepishly, I admit, I have no idea who George Grant was and he is not referred to in the pages of the book I referenced. I suspect the information I have is a much-modified version of the original, tailored to suit current techniques and materials. The author / tyer may not have any idea who the originator is?
Anyhow, if you need more-detailed photos or the recipe, don’t hesitate to ask. Good luck with it... I’ve had considerable success fishing it and it’s variants!!