Ok, so it looks like I have a good solution(s) for the Windows box.

I can very easily put the Linux partitions into files using cat or dd. Surely there must be a tool somewhere that can turn a raw partition file into a hard disk file matching either the VMWare or VPC format ? (the VMWare converter appears to be able to convert between VMWare/VPC and convert a couple of backup formats, but I can't see any way of converting raw partitions)