I think there were over 33 or more built but some went over seas.I know of 5 over the years
I Have two dart 12s in the yard The numbers I have are 32 and (33 I think)
I have a photo of 31 but I don`t think its yours.
I have a flat

top sail for it but we don`t have any py sorted for either sail. I would say with the inbuilt buoyancy in the sail you should work on a percentage (est 25%) slower than the 15 but in the right hands and a couple of youngsters they go well.
Cheers.
