Originally Posted by djetelina
Prolly cause it's 20 yrs old. Get something a little more modern w/ cartridge style bearings,
Why, because cup and cone bearing assemblies are completely useless?
OP - as mentioned earlier, take it all back apart. Could be a broken axle, could be a loose gap on the cone/locknut stack, could be related to the freewheel assembly, could be related to freewheel install. I'd take FW off and reinstall wheel into frame and see if it does it then. If yes, then you know it's related to the wheel. If no, then it's probably related to the FW.
BTW - are you talking about play (and sound) in the bearings while the wheel is installed or not? Off the bike, your older wheel should have a very small amount of play in the cup/cone. Once the wheel is installed, the QR skewer will compress the whole deal together and should take that very small amount of play out. Also, if not installed on the bike, and you are checking for sound, take the QR skewer out of the wheel - those things rattle around a lot. Some even rattle around a lot even when they're installed. (a friend's brand new Mavic Ksyrium wheels have noisy QRs)