I spoke with Grizzly and unfortunately they couldn't find a part to fit from other jointers. They have recommended that JB Weld will works as well without having to metal weld. Mine has a broken corner with a clean break so I am hoping it holds.
I just bought a Grizzly G1182HW 6" jointer and the fence support is cracked. Unfortunately the part is discontinued. Looking for replacement part PG 1182029 (PG 1182Z029).