Not well versed in Commemoratives or Special runs, but are you sure it was 1998, and not 1988? 

I can not find any “Official” Winchester Commemoratives that were US Marshall Bicentennial Model 94’s.  I did however find that Winchester (USRA) did produce a “Special Issue” run of 500 Model 94’s for the U.S. Marshall’s Foundation in 1988, to Celebrate the Bicentennial of the U.S. Marshalls from 1789 – 1989.

These 500 were produced with a Letter Of Authenticity from the USRA.  This Special Issue Run of 500 Model 94’s was commissioned by the U.S. Marshall’s Foundation.  Each was produced with a Number on the side of the receiver.  14 Karat gold plating on an engraved receiver, barrel ring guides and other items.  Select Walnut stock and forearms, with cut checkering.  24″ Barrel chambered for 30-30.

Wish I could help with a value but have no clue as to what they are selling for now, however it originally listed for $1995.00 according to what I found here on the WACA website https://winchestercollector.org/winchester-commemoratives/ hopefully that helps.

Gotta love that it’s value has increased as it has from $500 to $1995!