"Challenging" .
Got a set of drivers from LWS, Noticed one was loose. when I took the wheel off the axle, I saw that the axle ends had been "knurled" by hand with a pair of diagonal cutters--very crudely . They were all like that , and all out of plumb to there centers. Not the end of the world, as I over bored them on my lathe and turned new axles , but it would have been better if LWS had not attempted to "assemble" them.
It is my opinion that anyone who has not scratch built or does not have broad metal fabrication experience, must not buy these kits as they still show up on ebay.