Ajman Help For Non-Cto Mint Stamps

My understanding of Ajman stamps is very limited. I found the following artilce that I found interesting.

Very few stamps from Ajman are considered postally valid. There have been many stamps issued for Ajman, but a great number of them had limited, if any, postal use. The Scott Standard Postage Stamp Catalogue only recognizes Ajman stamps from 1964 and 1965 as valid. The remaining Ajman issues, primarily from 1967 through 1972, are excluded as their postal use appears to be questionable.

Are any of the ones I have considered postally valid? If so what value do they carry? Please, I need to invest back into my US collection I'm not looking for monetary gain.