I don't have a clue, I kept running across the same thing from Jim saying that Dr. Bramwell wouldn't disclose where/who he got the eggs from, lots of dead ends. It really doesn't matter all that much to be honest where, the important part to me is how it came about and what went into the pot. It sounds like the 'development' phase of the original stock was pretty short thus far which explains the variation that still remains from the Leghorn side of the cross. Aside of course from the work you and other hobby breeders have put into your own lines to guide them to what you want.
I noticed the picture of the "Whiting blue" or whatever we would call it has darker shanks (my personal preference). I know that there was enough variation in "U of A" blues that people weren't yet decided on what 'standard' should be. For me, I want dark/slate shanks if I can get them and large blue eggs
.