Section 31. The deputy director and town and district sealers shall keep seals for their use. The seal of the deputy director shall bear the letters ''C.M.'' and those of the sealers shall be of a type approved by the deputy director. Any sealer neglecting to keep such a seal shall forfeit not more than twenty dollars, and whoever, without being duly authorized thereto, impersonates a sealer or deputy by the use of a seal or otherwise, or has in his possession an imitation or counterfeit of the seal used by a sealer or deputy shall be punished by a fine of not more than fifty dollars or shall be subject to a civil citation as provided in section 29A.