Title a car with no VIN?

Someone else might have some good advice for you but I would suggest calling DMV and telling them what you said above and ask what needs to be done to get the car registered. Having a signed BOS is a good thing. Here in CA, for some vehicles, they request you bring/tow it in so they can inspect it and they sometimes will issue it a new VIN. Do your homework first. Don't divulge too much info on it until your confident that it can possibly be registered. Also, if you feel good about the initial call(s) to DMV, you may want to go down in person and find a sympathetic ear. If you can get a rep on your side, they can be of great help to you. Good luck.

PS How's that big paper mâché caveman doing in the center of town? ;)