I've been thinking to try a different carb in my Picco .28 Team Turbo also. I have 3 Piccos and I'm not so impressed with their carbs.

I have a RB S3 carb I and was going to see if it might fit. I also have a nice carb from a GRX.28 but the throat size is smaller than the Picco carb. I wish I could lay my hands on a O.S. carb sized properly.