I know I've read it somewhere before, but can you elaborate on the eye stripe thing?
Pullets are much more likely to have a solid, dark eye-stripe, like eyeliner. Head markings will be solid and consistent as well. Cockerels will have eye stripes that are lighter, but may be broken and head markings that are irregularly shaped.
It's not 100%, but it's pretty reliable. I consider any bird with broken light stripes and irregular head markings a roo until proven otherwise.