Good point. Generationally speaking, Mr Sheppard would have been almost at the original imports, and they could have gradually lightened from orange to the 'canary yellow and black' we're familiar with today.
On the old Ancona thread, a poster mentioned that their birds were autosexing at hatch due to a smudge/spot on the breast of the males. At the time, you had wondered if that was a trait of their particular strain, and they said they'd seen it in at least one line of large fowl and two of...