Put the crimp in with a pair of pliers, and a long flat piece of metal along the back to stop me crimping both sides. Used a small bit of wood between the pliers and the frame to prevent scratching, seemed to work fine, I have added a crimp of about 3mm and all is well.

My mesurements where based on the cranks not going full on because they where stuck against the chainstay, with the crimp, I am pretty much bang on I think.

Cheers for all the advice