Repair of damaged/corroded gold connector 'fingers'?

Recently, I've run across some circuit boards with damaged connector fingers. Some are badly scratched and worn, the gold plating almost gone, and others are actually corroded - the copper has corroded, possibly due to previous damage to the gold plating. The circuit boards in question are the ones in Nintendo cartridges, but the same problem applies to any printed circuit board edge connector. The scratched/worn connectors seem to still work, at least most of the time. The corroded ones wouldn't work until I cleaned off the corrosion. Not an easy thing to do - I ended up resorting to Brasso, a brass polish. Now, this is NOT the thing to use to clean edge connectors! DON'T DO IT! It WILL take the plating off. In this case, the plating was already gone, and the copper track underneath was corroded. Cleaning the corrosion off with the Brasso, and subsequent cleaning with alcohol to clean off the Brasso, removed the corrosion leaving a shiny copper track. The board worked fine, but for how long? How long until the corrosion comes back, or the copper oxidizes? Is there any way to repair or replate fingers like this? Obviously, tinning them with solder would prevent oxidization, but this would make that 'finger' much too thick, and risks damaging the connector it plugs into. (Operators loved to "fix" burnt edge connectors on arcade boards like this, and it works for a while, until you go to unplug and replug it, and the destoyed connector no longer mates with the board correctly.) Just something I thought that others might have an input on - I mean, in this case, these Nintendo cartridges are not worth the effort of any complicated repair, but it raised the question in my mind, and I know I've run into this on computers before. So, any thoughts? -Ian