Try Lant Insurance.
http://www.lant-ins.ca/collector.php
It probably falls under the "MODIFIED CUSTOM CARS, REPLICARS & STREET RODS" category.
They are now backed by Hagerty, which is good.
I was going to use them, but my current Insurance provided a similar quote.
It can't be a daily driver though!!!
You're driving record needs to be fairly clean as well.