Just chasing up the size of the king pin reamer and do you need the exact VW tool?

I use a sutton adjustable reamer with a pilot.
Best results for alignment between both bushes mean that a pilot is best.

The king pin has a nominal size of 18mm for type 1.

http://www.sutton.com.au/Assets/1346/1/IPD05Adjustable_reamer.pdf 
https://www.bolt.com.au/md-adjustable-reamer-tca-bright-p-96466.html 
https://www.bolt.com.au/md-adjustable-reamer-pilot-p-96447.html 

Also noteworthy is that the German king pin kits are much better quality,
and require less work for assembly that the brazilian ones.