hi Rizzo'
I am using 'Cinquecento' callipers on my conversion. You can get overhaul kits for these callipers from a company called 'BIGGRED'. I have dealt with this company--got first-class service. They do overhaul kits and parts for a very large range of callipers. Spend a couple of minutes perusing their web-site---I would be surprised if they didn't have a kit/parts that covered what you need.