SL never had a 10 year life period. Second generation was produced from 63 to 71. The third was produced 17 years 72 - 89. The fourth 89 - 01. Only the last one was produced 10 years and it is because the life of the cars generally gets shorter. Mercedes clings to 7 years time span between new generations only from the 90s. Even the 124 was produced 10 years.