Wow!  Sorry about the difficult luck with you Sand Hill Order, but I hope you reconsider.
As everyone begins to surf through poultry world there are a lot of elements to consider.  
Not all chickens are created equal.  Indeed, most end up failing the Standard.  The oft quoted number is that one in ten is worth using in a breeding program.  This, however, is a generalization, and is certainly dependent on the breed.  The commoner breeds are bred is high enough number that the gene pool is greatly diversified, but with the rare breeds this is not the case.
The three breeds you mentioned, Orloffs and Crevecoeurs, are so rare that I would be surprised if there were truly up to snuff fowl anywhere in the US or even the world--no exageration.
Crevecoeur are now so rare that if they are not soon adopted by a dedicated breeder their fate is sealed.  
What all of this means is that you can not get good stock in these breeds; it no longer exists.  Orloffs, crevecoeurs, houdans, redcaps, these breeds are all gasping for air like dying fish.  To purchase them is to know that your stock is going to be highly inferior and that you're going to work hard for several years to even begin to approach the Standard.  Too much white in an Orloff or some positive white in a Crevecoeur are, at this point in the game, the least of a breeder's worries.
As for Dorkings, well they're not as bad off as the aforementioned, but they're still not in tip-top shape--not even almost.  They, too, have been neglected for a very long time, and the result is degredation.  In nature there is no stasis; there is evolution or entropy.  You're going up, or you're going down.  Folk haven't been raising poultry commonly for decades now, which means that our breeds have been whithering away for a long time, and they bare the marks.
Silver grey Dorkings and Red Dorkings are the strongest currently.  Colored dorkings are a more problematic color pattern to begin with because it tends not to breed true to standard.  The whites are probably the most dangerously rare.  Rebuilding them is critical.  We have been working on it for a good little while now.  I expect good results in the next two or three years at which point, if the gov't doesn't find a way to shut it down, we will try to begin shipping them to make them more readily available.  Even then, they will still be a work in progress.  Multiple decades of neglect cannot be erased in a few seasons.
Try not to be discouraged, it can be so annoying to see all of these prize-winning white plymouth rocks or leghorns, knowing that our rare breeds are not even close to them in quality.  On the other hand, it really says something to get the dreggs of what remains of our rare breeds and resurrect them.  Anyone can buy white plymouth rock chicks from a breeder and win the county fair.  That takes no skill, and is no real prize won.  The one who can ressurect the Crevecoeur is a hero.
Cheers!