Hi, Gunmark is the importer (in the UK) who imported the gun your interested in. The Viscount is of course the model. They imported several different models from Arrieta and branded their own model names on them. Arrieta made these guns to Gunmark specs. Arrieta made guns for various firms the same way Zabala (also from Spain) did/does today.
The Viscount is a 5 pin sidelock the same as the Arrieta Model 557. Same sidelock pattern, different engraving. The model your asking about is a good quality gun. Arrieta is one of Spains top makers with a rep for producing quality pieces.
As to the asking price, 3k is a good deal if the condition is what you say it is.
If you can get the SN, e-mail Arrieta with that info and they will tell you the exact model you have.
Good Luck!
Greg
