Hope seem to have dropped the pdf file with the fitment guide for the numbered calipers from their tech section so I'm unsure what caliper would fit on those mounts.
Looks like an A2Z mount works as well which would let you use any I.S caliper.
captain slow dont suppose you have a pic without the caliper on do you? Yours has the same 2 holes like mine but thats not where your caliper is attached. And it hasnt got the mounts on the top stay like others h have seen