I've never seen a replacement for those without extensive body work. If there were, all of us with passenger vans would have them. Your best bet might be to find some of the elusive rear pop outs from an older van 9 (92-96?) from a salvage yard to match your existing pop outs and add screens. Also, a fantastic vent in the roof does wonders for these keeping air moving. It looks like you have a non-SMB fiberglass top, which is the easiest thing to mount one in. <$200.