Cast iron grate for Tailgater/Junior 20?

I just picked up a used grill for dirt cheap and the factory wire grate is pretty well used up. I'll clean it up enough to be usable in the short term but I was curious if anyone ever replaced it with a cast iron one. Traeger doesn't offer one for this model. I measured the original grate at 15-3/8" x 20". It looks like grillgrates.com makes their design at that exact size but it's quite expensive.

It looks like older 2-burner Weber gas grills use a 15" x 22-1/2" grate, if I can't find anything in the exact size I'm confident I could get generic cast iron grates for one of those and cut them to fit. But I was hoping someone had some specific recommendations.