The thinning of observe rim is due to a misaligned die, sometimes abbreviated MAD. The mint mark might be doubled, which would be a repunched mint mark, or RPM. A closeup image of that area is needed to be sure. The satiny look can come from dies that are fresh and have not yet stamped out many coins, often called an early-die state, or EDS. Personally, I'm a fan of early-die state coins, but even so do not think you coin carries a big premium because many other 1964 nickels exist in an early die state. Worth maybe 50 cents or $1 at best.