Dick, I don't think there are any special tricks on getting the booster out or decoupling from the master cylinder. Several places rebuild the Bonaldi, which I think was shared with Ferrari 246 and maybe Alfa Giulia. I'd had the Bonaldi on my Ferrari 400i rebuilt in Oregon and was pleased, I think it may have been "Booster Dewey" (and very affordable, and I was happy with the plating). Mr. Fiat and Apple Hydraulics also service this.
I also replaced the hard vacuum lines to the booster, the original short line near the engine was in poor shape and I replaced the long line with a stainless.
Master cylinder is from Fiat 130/Ferrari 246, and available at OKP--Lee