When you lay them all out, ready for painting, 622 incorporates quite a few subassemblies! Thirty-seven, in this photo, but I’ve left out the cab windows, so that’s another seven. Forty-four subassemblies in total.
While I had all the subassemblies in one place, I also took a few minutes to count all the parts. 513. That may sound a lot, but #10 incorporated 1162 parts. 3D printing, etching, die cutting and casting saved me from fabricating over 50% of the parts. What’s more, I feel there’s room for further simplification: I got lazy toward the end of drawing, and left some things to be modelled later. Perhaps the next engines will be closer to 400 parts.