Hi snapits,
I'm sorry, but I'm not a numismatist. I have no idea what a 1971 silver coin is worth. I follow gold and silver prices, not coin prices. In fact, most of the silver I've got is in the form of rounds, not currency. That was a good decision, btw. My rounds are up six-fold, but the premium assigned to the few silver dollars I have has hardly changed at all...
What purity is your gold crown? Probably 12 kt (for hardness). Gold is currently $1,680/oz. You'll have to take it from there.
Good luck!

Gold is $1,581/oz today. When it hits $2,000, it will be up 26.5%. Let's see how long that takes. - De 3/11/2013 - ANSWER: 7 Years, 5 Months