An update. Robert Pottinger's medals were sold in 1999 by Christie's:

http://www.christies.com/LotFinder/lot_details.aspx?intObjec...

Pair: Inspector-General R. Pottinger, Royal Navy, China 1840-42 (Asst. Surgn., H.M.S. Druid), modified straight-bar suspension; Baltic, unnamed as issued, contact wear and edge bruising, about very fine or better (2)