Dont get a dealers value. He will try to give you a low value so he can buy them from you at that price and sell it for a double profit.

Take pictures dont touch thim with bare hands, buy cotton gloves, and hold them by the rim.
Don't clean them you will DESTROY the value.
And I would not recommend offing them for money as they where your wifes father lifetime collection. And if you have children you could pass them down to them. (It is a hobby you will never outgrow)
I am very sorry for your wifes loss.