First thing to do was unwrap them.
Then a little time spent on the lathe to machine off the markings from some M8 countersunk bolts followed by a bit of a polish and I had the caliper hanger assembled ready to go on the bike.
While I was in the shed I stuck the front caliper on the fork leg (mainly so it didn't get lost/damaged)
Need to get some mounting bolts, probably wait until the Stafford show in a couple of weeks. In the mean time I've booked tomorrow off work to work on the bike. I'm hoping to have a roller by the end of the day (along with a big shopping list for Stafford).