The Guild SB-203 was the best equipped bass in the SB-201 / SB-202 / SB-203 series - three basses with one, two and three pickups respectively. Other than in terms of pickups and associated controls, all the Guild SB-200 series models had the same overall look, construction and hardware. All were set neck basses, with the classic Guild headstock and Chesterfield inlays of the B-301/B-302, and with much of the same hardware.
The bass shown below (from the 1982 Guild catalog) is equipped with two DP-8 single coil pickups in the neck and bridge positions, with a Precision bass style split pickup in the middle position. Typically production basses were fitted with three DP-8s.
The following text is taken from the 1982 Guild catalog
Our SB-201, SB-203 and SB-203 models ut through to let players showcase their talents to the fullest. All these models offer exceptional balance and feel, plus quality hardware like our adjustable BT-4 bridge and Guild deluxe machineheads with a 22:1 gear ratio
The 1981 Guild electrics catalog describes the SB-203 as perhaps the first bass to have three pickups. Whilst this exact configuration of pickups and switches was new, this was not the first three pickup bass - the Fender bass VI and Gibson G-3 both had three pickups