double headed amazon ????

Double yellow headed Amazon parrot?

Double yellow headed Amazon parrot?

I purchased a 16yr old Double yellow headed amazon from an individual and now that I have researched some more on the coloring. I am in question of is he really a Double yellow headed Amazon??? He has a yellow face and some red on his wings and looks like a Double yellow but his beak is gray??? Could this just be a sub species? Any Ideas or where to look for answers? Thanks any help! Teresa