My infills didn't fit, either, and the handle didn't come close to fitting into the slot cut in the back of the infill.
For someone buying a Kit, making a major adjustment to a mortise like that for a handle that is cut curved front and back is a tall order. the end result is the handle is more upright than I'd like, but not horribly so.
The cocobolo infills were narrower than the inside width of the base casting (someone didn't calculate future shrinkage very well). II had to purchase some veneer and laminate it to the infills (fortunately it's dark enough that you can't really see it).
The iron is poor quality (large strange chipouts every now and then - the only A2 iron that I've ever had that wasn't identical to almost every other A2 iron - that is, the A2 irons that are properly heat treated are almost interchangeable from brand to brand, but the shepherd is noticeably poorer).
The sides of the plane were drilled wrong so that the screw was not long enough to work with the lever cap. It shouldn't be near the end of it's travel at all, but it was well beyond even that.
Good idea, poor execution. It took me about 40 hours to put the kit together, about half as long as it would've taken me to just make it from scratch with *hand tools*.
Now I have a plane that is worth far less than the kit sold for used ($600 back in the infill sprint that occured in 2008 or 2009 when all of the infills on the market were high - the prices have about halved in the states since then). I would sell it in a split second for anyone who would pay what the kit cost me.