I have had a couple 27t TA Cyclotouriste (6-bolt). Not that it helps your situation, just for the record, TA made them.

I used one to do this Campy GS (steel) triple conversion. Obviously I had to lop off 3 of the original 6 bolt hole locations.



I wonder if Willow ever made a 27t in 74 mm 5-bolt? I know they made a 29t, I used one for this Campy Record Triple, with the "factory" 100 mm BCD, the smallest ring you can put on a 100 mm circle: