I read your post again. I think I will work with the Birchen. I could just have the Blue Birchen for layers. So many tough decisions.Ah cleaning up the silver ,good thing to do .
work only with your 2 birchen pullets ,they have a complete hackle and pure silver too .they will throw nicely colored cockerels and pullets for sure .
pen them with cockerel#1 and hatch 10 chicks from each pullet if you can ,than swap the cockerel .put cockerel #2 with them and do a same thing .
this way you end up with 30/40 chicks to select from .2 different combination .
when breeding it is better to hatch a large number from a selected pair than few chicks from a lot pairing .
chooks man