The 51 (actually 1952) legislation is also documented at the link.  You may wish to review it. No contributory pension plan, with the exception of voluntary government-run annuity schemes, was available until 1966 with the creation of CPP.   And governments did indeed use the EI surplus when it was available, and topped up the difference when it was not.  EI was largely unsustainable from the early 70s through 1996, when the Liberals changed the eligibility requirements, making it unavailable to those who left jobs without just cause.