I will be emailing Gozzoli today. I was meeting another Alfa racer with a 16v engine last night to see if he needed a set. Unfortunately not, but there are still 4 or 5 interested parties.
I have used the cam wheels with the multiple drillings in the past. They work well but are very time consuming to set up and test. Each time you want to change the cam timing slightly, the belt has to come off and the pulley unbolted from the camshaft.
Doing a DIY job by cutting out the centres of a second set of wheels and adding some slotted holes give the adjustability, but as Sprint 337 points out, it makes the cam pulley slightly out of line with crankshaft pulley. Whether it is enough to cause the belt to wear faster, I don't know, but it isn't ideal.
More later when I have a reply from Gozzoli.