Been tinkering in the shop a lot since jumping back into the hobby and am into my second ZW restoration... this one I'm taking all the way down to removing the core and levers..
One thing I've noticed on a lot of these 50+ year old ZW's is the levers rub very badly and are generally difficult to move.
If you cut some DIY washer/bearings out of an old milk jug (the material is generally HDPE and has been used for years in the Amateur Telscope making field as a low friction bearing material) - put one "bearing" on each side of the aluminum spacer - and you will have the smoothest levers you've ever seen.
