I bought a new connector-pin assembly from eBay a while back- my NES now works better than it ever did. I'd recommend going that route... the original assembly is copper, and even if you take it out and polish it, it'll tarnish again over time.
This here is the same seller I bought my assembly from- they're reliable, and I think you'll find the price ($9, including shipping) somewhat more reasonable.
http://cgi.ebay.com/ws/eBayISAPI.dll...category=41046