Like everything else, it's worth whatever somebody's willing to pay.
The big bugaboo could be the bore. Be prepared to prove to a buyer that the bore's not pitted and the breechplug's not frozen. In this area, stores commonly don't buy used MLs because so many have corrosion issues from poor maintenance.
If it were mine, I'd list it on Gunbroker, starting at or close to the lowest price I'd be willing to accept. That's to keep from giving it away. It's likely someone from one of the states with ignition restrictions will be interested. The expense of converting to a 209 system might keep those folks away.
