I don't know exactly when Gara was introduced, but it wasn't in the catalog as late as 1988. The oldest reference I have to it is from 1992. Gara was a plain gauge tubeset. It was similar to Aelle but used CrMo versus CMn, so was slightly thinner and lighter. Given the era and tubeset, I'd say the most appropriate Campagnolo group would be Xenon or Veloce.