My thoughts:

1. I wonder how many of these get bought specifically to be ridden in an Eroica event, and what fraction of them ever get ridden in an Eroica event.

2. People who restore old bikes have a lot of tools and methods to create something like this inexpensively, lots of other people don't, and understandably want something that can be serviced by a regular LBS with regular components... cassette hubs, threadless steeerers, integrated spindles.

3. I wonder if the Bersagliere guys would scoff at the newbs who showed up with derailleurs and pneumatic tires.