Looking for a Cat 980 window guard

Hello, I'm looking for a used window guard for a Cat 980G, 2KR series. Cat wants 'way too much for a new one. I can use a Cat or an aftermarket guard as long as it is brand name--it has to be an engineered guard. The Cat guard is PN 265-3936 or 264-3559 (I think the 3559 may be called a "landfill" guard.) These guards are all the same for 950G, H, 962G, H, 966G, H, 972G, H, and 980G, H. Can anyone help or direct me where I might find one? Thanks! Jon.