The Bell Lap does come in 26.0 and 31.8 according to salsacycles.com. I have a Moto Ace Bell Lap (26.0) on my Surly LHT commuter and it is working well for me. It isn't exactly a randonneur bar, but it might suit the OP's purposes. It does have an "anotomic bend" and double cable grooves so it isn't at all old school. Mine flares from 46cm at the hoods to 52cm at the ends of the drops.