120 miles with no plates, not wise. Not sure what the fine is but up here it would be more than the $10 for the temp plate.
As for NH, that old needs to have a Bill of Sale. The title may help to get plates in Concord, but all the ones I have registered, I have needed to get a form and have a police officer stop by to verify the VIN #. Which is always interesting as I have had to explain by there are so few numbers in the VIN and what they mean
This link may help, if not there is a contact link.
Registration FAQs - Division of Motor Vehicles, NH DOS
Hey, Concord's not far! Stay in touch