This is a circulating contemporary counterfeit Cap and Rays 8 Reales dated 1840 with the Go (Guanaxuato) mintmark and P.J. assayer.  This variety was not listed in Riddell's 1845 MONOGRAPH.  This example shows VF+ details.  There is a lamination through the '0' in the date.  Overall, this is an appealing example of a Cap and Ray 8R circulating counterfeit.