If you have a nice UK black hen or two use him over them and your lavender pullets and hatch a bunch to get a few good ones. Even the best breeders average only one in ten to replace their own stock. Then if nothing is great and you have some good ones buy a good male somewhere if you can. Don;t go crazy and keep buying birds.I am such a newbie. So breed him to the silver birchen? Would it be easier to search for a different roo to cover the two pullets with the squirreling? I got them from the same place and did not notice it much when they were little.