RSA 450:2: For Labor.

Any person who shall, by himself or others, perform labor, furnish materials, or expend money, in repairing, refitting or equipping any motor vehicle or aircraft, under a contract expressed or implied with the legal or equitable owner, shall have a lien upon such motor vehicle or aircraft, so long as the same shall remain in his possession, until the charges for such repairs, materials, or accessories, or money so used or expended have been paid.