I was working on the little bracket thing on the right last night. Spent about an hour, but then it didn't fit. At first I couldn't understand it, but then I realized I had built my frame a little thicker than the plans called for since that was the thickness of the wood I had.
So now I need to be mindful that when I'm making parts that fit along the thickness of the thing, I've got to measure against my own machine "as built," and just use the plans for guidance.