The problem with exporting large carriers is the manpower requirements & operational costs, which are too much for the mid-size navies that would be in the market for such a ship. This is particularly true with the Essex-class ships, which the RAN considered in the mid-60s as a replacement for their two CVLs, but rejected on those reasons, as well as the current crop of US carriers- there were some proposals a few years ago that involved India buying a Forrestal, but that too was quashed on grounds of excessive manpower and operating costs (not to mention that they were just a bit clapped-out after some 35-40 years of active service.)
As far as surplus carriers for export, what the US had that would have been suitable for the buyers in the 60s would have been the CVEs & Independence CVLs, but those weren't really adequate for the jet aircraft even of that day. Even the 'small' CTOL, ASW-oriented design studies the USN had in the late 60s & early 70s were pretty big in relative terms, falling between Midway & Forrestal in size and manpower requirements, IIRC. Australia did take a look at a derivative of the Tarawa-class amphibious ship in the early 80s, but that probably would have been restricted to VSTOL aircraft and was considered too expensive.
For the first 20 years post WW2, the best available carriers suitable for export to such navies were the British light fleets (Majestic/Colossus classes), which although slow, could function as a functional CVL with the carrier jets of the 50s & early 60s, if a bit limited in operational capability.) Had more Centuars been built, they would have been better suited- faster, better able to operate high-performance jets, but the same compact size and manpower/operating costs as the earlier light fleets, and those might have dominated the export carrier market.
From the mid-60s onwards, the best available fixed-wing export designs in that they are capable of operating modern aircraft but not too expensive to operate would probably be derivatives of CVA-01 or Clemeanceau, but after that, I'm not really aware of anything off-the shelf that could be workable until CVF came along- there are some rumors that Brazil's interested in a derative around 2020 to replace the Sao Paulo. The Russians aren't probably being seriously considered considering the way India's been getting shafted over the ex-Gorshkov (which is leading India to start building their own) For the navies that might be interested in such a ship, I'm not sure how practical having a custom-designed ship, even if a updated CVA-01 or Clemeanceau, would have been.
Of course, the likely buyers (Australia, Canada, Argentina, Brazil, Chilie, perhaps Italy), would have needed rather more generous defense budgets from the 1970s on to be able to procure and operate such a ship and its escorts, and to have a strategic policy that would have a use for such a ship.