I stand corrected with respect to the total number of participants and boats.

63 boats.

43 from Italy + 1 Sam Marino
6 from Germany
8 from France + 1 from Monaco
4 from Switzerland
1 from Spain

In the remaining listing there were no internationally known name as far as I can tell.

Wouter

Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands