Most of the following information was suggested by members of the CorvairListServe:
Chip Lennemann at Aerospace Risk Management Group 517-669-8308 is a broker who has obtained insurance coverage for a number of the members of the list serve.
Falcon Insurance in Florida
ChartisNation Air covered me on one of the members in a Piet / Corvair combo. 877-475-5860
AUA - covered one of the member on his first flight but with a VW. Greensboro, NC -based.