Thanks a lot guys. I DO have several filters, and I can't seem to find a series 6 polarizer (which I nearly always use in color film) or any infra-red filters either so I definately want to adapt to threads.
I don't mind stacking step up rings so series 6 to 7 and 7 to thread would be great, but I can find a 6 to 7 anywhere.
I may look around for a machinest, otherwise I'll try the series 6 to glue adapter. Both very simple solutions, and I'm disapointed I wasn't able to come up with them on my own.