Just about anything marketed as a "sport-touring" bike in the 80s is going to have geometry a lot like the current Rivendells, etc.

Were I looking for a comfortable and fast "vintage" LD bike on a budget, I would start with one of those.

If budget is not a consideration, then as Road Fan points out the French randonneuring bikes of the 40s, 50s, and 60s are probably still the best bikes ever made for LD. Prices start at around $5000...