I have acquired a large collection of binders filled with China stamps. I have been looking to find some gems and came across this one. It appears authentic with raised ink but how else can I verify that this is the 1980 year of the monkey stamp?
Also, I posted scans of two similar scarlet colored Hall of Peking stamps. Is there a way to distinguish these two besides the Scotts numbers?

My dad used to collect these and recently moved. He did not want to take all these binders to his new home and was done with his stamp collecting hobby. Your help is appreciated!
Kathy