NIce to hear from you again. If you start with cuckoo marans use them for females. Like that, boys will be barred ang girs black or birchen. After, breed them back to old English male. If you are using birchen marans, it shouldn't matter. Try to find clean legged birchen marans otherwise it...
Originally, Fred Myhill created norfolk greys from birchen old English games and partridge wyandottes. To recreate this breed is better to not use wyandottes because of the recessive yellow skin genes which will be difficult to elliminate because this gene will hide behind the white skin and...
Sorry OIG is Old English Games.My mistake.Cakle Hatchery have them.Valentine's Hatchery have birchen marans you can use whith OEG and work for elliminating feadering on legs.