A few weeks ago, I ordered from Stuart Turner, a pair of castings for the bottom main bearing brasses, for a number 9 engine that I have had "on the back burner" for some time. When they arrived, a preliminary measure up showed them to be undersize. I rang Stuart's, and they said it was due to new patterns being smaller, and that the drawings were being amended to suit. This is fine if you are buying a complete new set, but not if you want a replacement for an existing model. Stuarts solved my problem by sending me a couple of rectangular blocks of cast gunmetal. I did suggest that it would be helpful to put a note about this on their website. They said it was currently being redesigned. Meanwhile, beware of undersize castings!