I'd forgotten how much fun it is drafting pattern blocks. The Aldrich book has size charts from a British standard, and while they are odd in places (scye depth of 5.5cm for a one year old vs Aldrich's 20ish for a 2 year old?!) they are a good place to start. I've always liked maths, and drafting blocks is a simple process of following a plotting plan. You need to pay attention, but there's no complicated working out to do. (I did make my own decision on the scye depth by what looked right to my eye though.) So here's my completed block for an overgarment, via the basic bodice block.
And here's the sleeve. It has a very high looking sleeve cap, and the curve still looks a bit pointy, but that's what toiles are for! Next stop is to make a quick toile to see how this block works. I compared the pieces to the pattern I used for Nicholas' jean jacket and was pleased with the comparison. Just not sure about that very high sleeve cap.