These things are great, I had a set on My IPRA 1600 - sold in 2002. Exactly the same set-up.
The only trouble was finding pads and rebuild kits for them. In the end I took the Calliper to Race Brakes up here in Sudney who matched all the seals for me. For pads, I had decided to get some backing plates made, and was going to have new pad material bonded to them. I never got to that point though - Sold the car just prior to needing to replace them.
I ran 13" hotwire style rims, worked a treat! I was able to out brake most of my competition at the time.