I have a Holdsworth Mistral and as it has rack mount bosses I believe it is a 1983, the only year they had them. (Please do correct me if im wrong)

I also have a Gipiemme Dual Sprint double crankset which I wish to fit to said Mistral.

So....it is ISO, and the arms are straight but I have no idea what length BB spindle I require and after much head scratching I thought I'd ask people who are almost guaranteed to know more than me. On One Cycles say thier 110mm will fit nearly all ISO but then say 113mm if you buy thier Holdsworth cranks!?

The BB in the frame is give or take a knats whisker 120mm but pretty confident its JIS and dont know what cranks were on it so no help.

I shall return to my trusty Surly LHT and await your collective brilliance.

Thanks for listening.