Don't be surprised if the cogs don't want to unthread easily. Years ago I worked in a shop which specialized in custom gearing. We often built up Maillard, Atom, Regina and of course the two S's freewheels. The Euro ones were always a pain to deal with. Often the biggest cogs were left hand threaded and went on from the back side. Having a way to hold the freewheel body tight enough to loosen the last cog will prove to be a challenge. Good luck. Andy.