The Washburn Mercury MG104 is part of the Washburn Mercury I series produced between 1993 and 1996 under Grover Jackson. The Mercury I series were manufactured in the United States and were regarded as high-end instruments. The MG104is similar to the Washburn Mercury MG94 but has a Quilted Maple top. The MG104 also features an Alder body, a Schaller Floyd Rose Licensed tremolo and direct-mounted Seymour Duncan pickups in an HSH configuration. The neck pickup is a Seymour Duncan 59 humbucker, the bridge pickup was a Seymour Duncan Custom Custom and the Catalog mentioned the middle single coil as a Seymour Duncan Custom hot.
The fretboard was either maple with black offset dot inlays or rosewood with pearl offset dot inlays. The headstock featured a 14 degree angle, Schaller tuners and a locking nut.