I just checked ebay and there are 3 like yours selling for 30, 40 and 60 bucks. I have seen them go much higher restored. The ones on ebay now are all in unrestored condition like yours. I will try and post a link to one that cleaned up pretty nice. Looks like yours except cleaner and sold for $147.50 last week.
http://www.ebay.com/itm/48-49-50-51-...p2047675.l2557