finally, found a supplier in the UK who does a very nice set of brass bushes and very affordable. Sells them on ebay. Been struggling with several stock carbies, even brought a cheap repro 34PICT-3 but then I found these mentioned somewhere online. Good thing is, you dont necessarily have to dismantle the throttle shaft to replace the bushes, you can pick the old nylon bushes out with a pin and slide the new ones in.

Success ! A stock carb I can tune, what a difference !

search on seller name robinson129434 on ebay
or vw camper /beetle solex 31 /34pict 3 carb repair bushes AIR COOLED

http://www.ebay.com.au/itm/VW-BEETLE-CAMPER-SOLEX-31-34-PICT-3-CARB-REPAIR-BU...