Hi all,
I am truly appreciative of all of your feedback, and I am particularly grateful to Mark and Pete for taking the time to explain things. I don't ask these questions out of spite, but because I want, no, need to understand. I am not the kind of person that will follow stipulated ideas or methods simply because somebody has stipulated them. I have a deep need to make sense of things for myself, and your explanations do help a great deal. And I am listening.
As far as the kits are concerned, it's just one of those lessons that have to be learned. And yes, the non-centric threads do also cause the top not to sit flush on the metal part. But I can assure you that none of the surfaces came straight off the bandsaw. Looking at the pictures again, I also realise I should have cleaned them a bit more, there's quite a bit of dust visible, which is not good, either.
Again, thank you all for your time.