Military judges, military counsel and members of courts-martial and courts of inquiry shall be allowed transportation and per diem pay as per military grade for time actually employed in the duties assigned them. Transportation shall be furnished to all prosecutors, prisoners, witnesses, sheriffs and police officers to and from the place or places designated for the meetings of such courts. The per diem pay for civilian witnesses shall be the same as in civil courts of law and for military personnel the amount as provided by law and regulation. The fees of sheriffs for serving the processes provided for in sections 40.005 to 40.490 shall be the same as prescribed by law for similar processes of a civil nature and shall, upon proper vouchers being filed, be paid by the adjutant general in the usual manner.