Hi, everybody, and thanks for all of the input.
I have finally resolved it, after speaking directly with supervisors at both Hagerty and ICBC and Ontario MTO.....
While the truck is under restoration/modification at the shop in B.C., Hagerty is covering things even though I live in Ontario and have the truck in a B.C. shop and still registered as a B.C. vehicle. Hagerty will re-evaluate periodically as the work is done, upping the coverage as value increases.
When it's time to bring it home to Ontario, ICBC will issue 3rd-party liability insurance with the 15-day temporary permit and Hagerty coverage will be for the comprehensive side of things.
Before I come home I will also transfer the vehicle into "unfit" Ontario status, locking in the sales tax on the value before the updates. When I arrrive in Ontario I will then get safety certificate and plates for the road.
All sides have agreed that this will work in my unique situation and I thank all of you for your input and advice.... wink