Reales are silver. If you have a gold coin, its either a plated real or an escudo. A picture and details as to the weight in grams would be invaluable as to identifying what you have.
I'll bet this is your coin; actually, the base metal is silver; yours was probably gold plated. You have described it elsewhere as showing 'RS' to the left and 'IPA' to the right of a shield--as with this coin. http://www.coinfactswiki.com/wiki/Image:SPN_1733S_1R-PA-obv.jpg
Don.....
PS: The R and I represent 1R; the S=Seville and PA are the initials of the assayer.