The risers were modeled by Empire on my car, which obviously has the larger holes, although at the time we thought all the holes were the same size, and of course they fit perfectly, but we are finding about half the kits that have gone out are having the same problems as Laurens. Because there is less leverage on the original track rod end, it isn't quite so important that they seat properly, and the taper is enough to hold it in place, but once the riser is fitted, there is extra leverage because of the height, so it is vital it does sit square on the steering arm. The two options are to either put some shims under the base, though this is not really recommended or better still, take the original track rod ends and the new risers to a local machine shop and ask them to take a bit of metal off, so they match the originals, so they will fit all the way in.
A bit of a pain, but something else that we have to put up with as Morgan owners.
And, having put a few kit cars together over the years, I can wholeheartedly agree that it is just a kit car, and not even put together that well in places, but I am learning that this defines the Morgan.