I'd go with a 110/74 bcd triple as well.
My 1984 Trek 610 has become one of my favorite bikes. It has classical sports touring geometry with long reach side pull brakes. I'm running it with a 110/74 bcd shimano 600 triple and 3 x 7 gearing and 700 x 28c tires. I think I'm going to "modernize" the bike with indexing,