depending on how you feel about the offer (Can you replace your bike with the offer?), your best bet might be talking to an lawyer in your state. Did you use one at all for your medical?
I sounds like Bull to me, I don't see how an insurance company can destroy a vin. If you want a new frame you can buy one from Harley, You have to send them the old so they can destroy it, and then they'll give you a frame with your old VIN stamped in it so everything matches. I don't know what it would cost or all the details, or if it's worth it. IMO if you can do the work yourself and want to spend the time fixing it, or making it custom it's worth it, but if your gonna have the work done by someone, just junk the bike and get a new one. Just make sure you can get a new with the settlement, if you can't don't accept it until you can.
Maybe he meant it couldn't be registered until fixed and inspected......I know in Washington state, that you can register a non running Bike, or any other vehicle for that matter