This list has a number of boats in your size range that were produced later than the 1970's.
Mahina Expedition - Offshore Cruising Instruction
Not many made it into the 90's or the
current decade and those that did are typically quite pricey like the Bristol Channel
Cutter or PSC Dana/Mariah etc.
If you are on a
budget...you'll probably need a 1980's
boat to hit it. Check Westsail, Capedory, Baba, Yankee within your size limits for capable boats at reasonable prices.