they can either have a big upright comb or a comical one both are ok, there is no standard. i love the hens with the big flopped over combs. similar to dorkings.
i look for leg issues and spine issue, with such long quick growing legs and bodies you want them straight and sturdy.
the males are especially awkward young with the long legs and can be injured easily.
i crossed a bresse with one recently will find out in a few months how it works out. also one crossed to an isbar and it came out beautiful. both will improve on their laying ability i think.
i also just started two on turkey starter for their first 9 weeks to see if it gives them a boost - friends have had good luck with this for 'wilder' birds like these.
also make sure when you process them to make stock from the head and feet separately. there is so much gelatin in them, more than any breed i have ever seen. you can get 4 qts from a head and feet alone (a little vinegar, cover with water, bring to boil then turn to low for 24 hrs). then another 4 from the carcass later.
Thanks again for the info. When it comes time to process I will be asking for recipes. I'm not accustomed to cooking with heritage chicken yet.