Mo. Rev. Stat. § 302.308
302.308 Effect of conviction prior to enactment.
302.308. Effect of conviction prior to enactment. — The director in warning an operator of his conviction record or in issuing an order suspending or revoking his driving privileges shall not convert to points or use as a basis of suspension or revocation any conviction which occurred more than six months prior to the effective date of sections 302.302 to 302.309 , provided, however, that such accumulation of points resulting from convictions prior to the effective date of sections 302.302 to 302.309 , shall not cause a suspension or revocation of any driving privileges, not suspendable or revocable under the law existing prior to such effective date * , until there has been further violation or violations under the provisions of sections 302.302 to 302.309 .
(L. 1961 p. 487, A.L. 1989 1st Ex. Sess. H.B. 3) Effective 7-27-89 *The original effective date of this section was 10-31-61.