Under these circumstances I was pretty happy to find a set of NOS (although not Fiat OEM, but hey) rear brake cylinders on Ebay for $17. I find Ebay has gone way downhill after my selling heyday on it in 1998, and haven't really looked at it in quite a long time, but just on a whim I had a look for Brava pieces with this result. The front calipers can be rebuilt pretty easily and cheaply (I have experience with this from the Spider, lucky me), and we'll likely need a master cylinder, new hoses, and possibly the rear compensator. Fiat brakes have a really awful reputation, but from my experience they are pretty good if done properly.
My timeline calls for the Spider to be running in a couple of weeks, and the long long July 4 weekend should see us cleaning the fuel system on the Brava and getting it started.