There might be, well, other options. Can you get liability-only coverage? That's sometimes easier to get than full coverage. Would the financial loss be catastrophic, if the plane is damaged?
I wouldn't want to fly without liability coverage (to protect my family's interests), but I haven't had hull coverage on any of my planes since I got rid of the last a/c financing note (and an a/c partner) over 20 year ago. I probably have roughly the value of another plane in savings and investments, from the money I saved on hull insurance. I wouldn't *enjoy* the financial loss of the plane, but it wouldn't have any effect on my ability to pay the bills.
If you or your family can't take the financial hit, then obviously, don't do it. But you're already 80. Even if insurance pays off on a 'bent' a/c, will you get it repaired in time to fly again?
Get 'current' (BFR) in a Cessna, or whatever is available in your area. Then you can be PIC, assuming the financial risk. At that point, there should be more instructors that could get you checked out in the -12. (Unless there are just no instructors in your area you trust; that's a different problem.)