This seems a bit of a daft thread really - why hypothesise when you can just ring round some insurance places and see if they're likely to insure you, and if so, what the damage will be.
No doubt some places will offer to insure you, it'll all come down to your budget. Try all the tricks in the book. Don't always assume garage is cheaper - It was cheaper to say I park mine on my drive than in the garage. Having my mum on it lowered it, but my dad made it go up, and my partner was a no-go too. For some odd reason I was always best with admiral on my jap cars, but they were rubbish with BMWs.
It'll just take time to find the cheapest quote, but I suspect if you're trying to insure a skyline at 19, the word cheapest might not be very appropriate!