§ 153. Transfers. Transfers from one town police department to another town or village police department in the same county may be made upon the mutual consent of the appointing officers of the departments affected. Any member of such police force who is or has been transferred shall receive credit with the department to which he is transferred for time served on the police force or in the department of any village or town within the same county, as though the full time had been served with the department to which he has been transferred, for purposes of seniority, promotion, pensions and general administration.