Have an electronic assay of the coin done and I'll buy it. Your printout is not proof. It id proof that a gold coin was purchased from a reputable dealer. Not proof that coin is the coin purchased.
I believe a few trusted escrows may have a Sigma Metalytics Precious Metal Verifier.
Not sure if that would satisfy or not, but it would verify if the coin is .9999 24k gold or not.
thanks!