The tricky thing about Golden Cuckoo is there seems to be no standard for which e allele it is based on. flgardengirl's is a barred blacktailed buff. Most are barred black coppers, but if there is a barred wing triangle, then it can even be barred wildtype (golden salmon).
I believe most standard (silver) cuckoos are EE based, solid black bird with barring. I have seen some that are definitely silver birchen based because the hackle on both roosters and hens is much lighter than the rest of the body. (like the ones in the picture on the Marans of America Club website)
So when "creating" the golden cuckoo and introducing the gold gene, crosses had to be made to black coppers (the most likely choice for egg color). But then you get a mix of the extended black (EE) allele and the Red Birchen ER allele in the first generation, and probably don't get good "golden" until the second generation bred again to black copper.
We know that certain lines of black coppers throw dark wheaten, and that these dark wheaten can throw blacktail buff (just add the columbian gene) So if any of the black copper used in the cross to make golden cuckoo were from these lines, you can potentially see barred wheaten, barred silver wheaten and barred blacktailed buff.
In addition, if the golden cuckoo rooster used doesn't carry double factor barring BB and is instead Bb, then he will throw some plain BCM hens!
HenThymes' lighter chick looks silver based to me, maybe silver wheaten? If it's a hen the barring won't be very easy to spot.
The darker one looks like it could be barred blacktailed buff like flgardengirl's. It doesn't have the defined chipmunk striping of the typical golden salmon wildtype, and the feathers are showing some of the pattern gene Pg that creates spangling or lacing in some breeds. But it could just be the way the barring is showing up. I have barred crosses that show every level of barring from barely there, to strongly defined. If he's a roo and carries double factor barring, then the barring will be more distinct.
It will be very interesting to see how he feathers out.
Keep posting pics!
Debbi - I just had a 2 out of 14 on shipped eggs!