Subject to the prior written approval of the Insurance Commissioner, any life insurer licensed and doing business in this State and still having outstanding and in force funeral expense contracts issued prior to January 1, 1968. or reinsured thereafter, which contracts provide for payment of death benefits by furnishing goods, services or merchandise or cash, may over a reasonable number of years establish reserves on such contracts. Subject to prior written approval of the Insurance Commissioner, amounts for the reserves on such contracts shall be calculated by using: (a) mortality tables recognized by the Society of Actuaries or by similar organizations; and (b) current interest rate assumptions. Upon establishment, such reserves shall thereafter be maintained unimpaired by the insurer unless lesser aggregate reserves are subsequently approved in writing by the Commissioner upon the insurer's written application. To secure the Commissioner's approval for a cash reserve plan under this Rule, the insurer must pay cash benefits for policy claims.