I believe they made at least 9 models / grades of sxs. There was the 502. It was a sidelock with Purdey type bolting, Articulated trigger, demi-block, Holland automatic selective ejectors, hand detachable side locks. They also had the 801 Deluxe, with more engraving and upgraded walnut. Their top was the 802 Eagle, with all the above plus special engraving.

Pete