In that case, I would want to keep the Russian Pavlovski or Pavlovskaya (depending on whether you want to use a masculaine or feminine form of the word. I've seen both). It is thought to be the ancestor of the European crested breeds like la Fleche, Spitzhaubens, Brabanters, Polands, Sulltans, Crevecours, etc., many of which date to before 1600. The Pavlovskaya looks like a gold Brabanter with feathered legs. Greenfire Farm has brought some to the USA, but it will be a while before I can afford any.I think Iva and Geo. both have some really sound ideas. This is sort of like what I've been saying for a long time.
I wish folks along with their favorite old breed would also keep one of the foundational breeds: those I refer to as Ancient (pre 1600) and Modern (1600-1845). These are the breeds which cannot be replaced whereas all composite breeds theoretically can be. Unfortunately, most folks it seems think more of their Rocks and Reds than they do the breeds that made them. I have nothing against these Industrial breeds and think they should be preserved. I only wish they'd think through the whole preservation idea a bit more deeply.