BPS Hunter model ...is available new in a 28ga... and list is $ 700 ...probably selling new for around $ 600...
http://www.browning.com/products/cat...id=012&tid=211
silver nitrate receiver, engraved....I don't know what it could be...
(maybe someone mis-labled it ??)....but Browning does make quite a few guns, as special orders, that are not in the standard catalog as well. ( as an example, I have a pair of Browning Citori XS Skeet model O/U's .. one in 28ga and one in .410 that were both made by Browning on their XS Skeet 20ga receiver...but the 28ga and the .410 are not in the catalog. A dealer in my area, ordered 50 of each gague from Browning some years back in the day ...and a guy was talking at my club, that he had found one, and onone could tell him what they were - or who made them...)...