Looks like a mix of old and newer. The narrow wood slats and part of the frame are newer. The older frames had a single lower bar on the bottom where yours has two. The control panel, black knobs, fuel gauge and wheels are older.
No matter though, they all cook the same and look good cleaned up.
Nice find!
Edited to add:
Disregard what I wrote above. Your grill looks just like the one in the 1990 product brochure. Nice find!
Gerry