TA rings were considered superior to Stronglight. So the people in the know (among French cyclotouristes) chose 49D arms with TA rings. And yes, TA rings are still made. Any size you want, I believe, up to something ludicrous like 74 (bigger is special order, I have seen a 100+ ring at Bicycle Specialties in Toronto).
Jan Heine, Seattle
Jerry Moos wrote:
I suspect a lot of bikes in the classic era had mod 49 arms with TA rings, as TA rings were widely available, and had a wide selection of ring sizes.