I have 2 of these x000 grills right now. The older one is a 1989 model, the other one is clearly newer but has no serial #. There are some small, but interesting differences. One of these differences is in the way that the swing up table is attached. On the 1989 there is a metal tab screwed to the frame and the pivot rod runs through that, just like Andy's. On the newer model the pivot rod is connected by a plastic insert in the end of the frame rail.
Also, on my 1989, the end of the lid handle is visible (again, like Andy's), whereas on the newer model the part where the handle attaches has an extra bit of metal that covers the end of the handle.
A couple of other interesting differences between my two grills: The older one has mounting sockets for one of those swinging baskets in the lid, the newer grill has mounting points for 2. The frame rails on the older grill extend a few inches beyond the control panel and there is a small basket there, on the newer grill those frame rails are flush to the end of the control panel. The fuel level indicator rod on the older model is straight and lives on the outside of the leg, under the control panel. On the newer model the indicator rod is a z shape and lives inside the leg, under the grill.