I say from most of the general population it's just an old ten speed bike and think a lot of stuff like this got tossed when found. Same goes for anything people who don't follow a certain hobby and come across something special. Why the need to consider it stolen.

Get some degreaser, hose it down with and cleaner her up. Take her down to a shop and ask how must to get her back on the road. I say two hundred tops for a complete overhaul. Most of the time shop will include install labor with the purchase of their overhaul packages. That two hundred or so sounds like alot to drop on a bike you have no interest in but would make the bike more sellable...it's a Richard Sachs so along the lines of something with Carroll Shelby's attached to something auto related. It won't be hard to sell as it will sell itself because of what it is.

You could toss it on ebay and let it ride but selling something at Xmas time isn't the best but people always treat themselves to presents so who knows? Also Richard occasionally posts in the framebuilders forum as e-richie I believe.