Just to clarify.
I need an adaptor to mount an IS fitment caliper to a post mount fork with a 160mm rotor.
This will have all plain holes with no threads.
I've got one somewhere for a 180 (or are they 185?) rotor. I looked into this a couple of years ago and came to the conclusion there isn't one for a 160 and ended up buying a larger front rotor only to change my mind and use a different brake set. I could be wrong though.