Will you be willing to ship eggs then?
Yep!
I have every egg marked by pen and there are a lot of them. Well, I don't mark the Ameraucanas - they are the only blue egg layers I have!
BBSO - Blue/Black/Splash bantam Orps - Father is 100% English.
BMF - Bear Mille Fleur (Bear and his 3 girls)
MMF - Mixed Mile Fleur (a winter pen with all but 3 girls and 1 boy)
Cho - Bantam Chocolate Orps (2 pens)
O - Otis - Bantam chocolate Orp over black bantam Cochins
J - Jamie - Black/Blue bantam Cochins
T - Tom - Black bantam Cochin over bantam chocolate Orps
E - Ego - Black/Blue bantam Cochins
My eggs all get marked with date collected & which pen...but my flock is diverse enough I can usually tell which hen laid each egg or narrow it down to 2 or 3 possibilities. If I see an issue & need to know for sure I just separate those couple of hens.