let me explain you how EASY this breeding program should be..
let start with the fact that is: Lemon Cuckoo Orps are just Buff Orp with the sex linked barring gene, thats it. so if anybody has issues with type, color(blackshowing on tails) the easiest way to fix this is to outcross to good quality Buff Orp pair.
this is how its going to be.
LCO male x BO hen
Select the best barred F1 females and cross them to Buff Orp Males.
Select the best Barred F1 Males and cross them to Buff orp females.
at this stage they should have regained good Buff orp qualities. and you can continue breeding the best barred males with the best barred females..
Females cant be double barred, they only have one copy of the Z sex chromosome where the barring gene is located. their other sex chromosome is W. so females are ZW and males are ZZ(thats why they can have two copies of sex linked genes) the W chromosome in the hens is as useless as our own Y chromosome in humans, small and almost void of usefull genes