Do Kibler's kit parts require any fitting, or do they drop right in?
Parts are made very close, but that does not mean there is zero fitting required. Kibler's intentionally errs on the side of tighter tolerances rather than looser ones, because loose tolerances would risk visible gaps. Fitting needed can range from essentially nothing to a bit more work, due to normal variation in the machining process and because humidity differences between the shop and a builder's home climate can affect how wood parts fit.