tomc,
I have one of the Austrian military versions and one of the Italian version actions set aside to build a 6.5x54 MS on.I am so far from you that it would be easier to find someone closer to you than come here. You are lucky the 6mm fit,reworking the spool is not easy. There is not much difference between the head diameter of the 35Rem and 6.5x54MS, so you should only have to worry about the forward part of the spool.
Mike