I agree with Tom Doak. It seems to me the first true effort to restore a classic golf course was undertake by Karl Olsen at the National Golf Links of America beginning in 1986, I believe.
What's most interesting about The Country Club is, the work done there in preparation for the 1988 US Open marked the first time ever, I think, that a golf course was "restored" in preparation for a championship. Until then, it was widely thought that in order to host a modern era US Open, the golf course had to be "modernized".
How about the revitalization of Augusta National following the Second World War? The golf course closed for a few years during the war (1943-45, I think), when sheep and/or cattle grazed on the property. They must have undertook some extensive restorative-based work in preparation for the 1946 Masters Tournament, I imagine.