Working in a book/toy store, I can tell you that young boys are by far the worst off.
Until the age of 10/12, you have sweet jack all that's not Postman Pat or Bob the Builder. Maybe Dinosaurs.
At 10/12, you get access to Pirates/Football, and then you get into the whole Horror/Science area.
Girls though? Girls have chewed up everything boys had - half of them spray it pink and half kept it as it was.
Venus, the fifth Ninja Turtle, was hated with a passion. And there's never a time where an age where a Tiara doesn't sell.
While I'll make sure you have a list of stuff to use Bob, I wonder if you've ever seen the sheer level of hatred thrown at the child who chooses the "WRONG" toy?
Honestly, picking up a pink notebook or a doll can be met with horrified looks from some boys parents, and a girl's Meccano set? Well, it's going to have the be painted pink (No, I'm not joking, there's pink Meccano for girls) or they may as well wave goodbye to the idea of grandkids.
And as for age? Unless the age is specifically stated on the toy, the parents/guardians are totally lost. I've actually been told that it's ILLEGAL for toys not to have the recommended age written on them.
But I'm rambling...prepare for a bringing up to date