If I was going to find new vintage territory - it would be in the direction of Ridability over Collectibility. Free hubs over freewheels, integrated shifting/braking, dual pivot brakes, etc. Essentially a move to the 90’s. I can live with 25mm tires.
As far as a bike addition to my group??? I guess I need a higher quality French bike.
I no longer seek Grail (bikes/framesets) but I am actively working on saddles and the requirements for greater cockpit comfort.