They made a Spirit 500 which was 2 burners, the 700 which you have and a 900 which were 3 burners. It was their first foray into 5 bar grills only made those for a few years. They still made the Genesis but the Spirit was a lower price point looks like a nice one you have there.
On the other board a member added casters, think he cut about 3/4 off the legs and just plugged the casters in.