Compared to #10, the crosshead and guides on #622 are going to be a bit of a nightmare. First of all, they follow the raised pattern, which is going to make them difficult to locate vertically. Secondly, they are not plain bars, but are shaped to provide strength where the thrust from the connecting rod is the greatest.
Assuming they’re going to be formed up from layers of etched nickel silver, there appear to be about 5 1/2 layers stacked vertically to create the guide bars. Fortunately, I can assume that the 3D printed cylinder saddle will have thin walls, and so there should be room for a tab off the frame to hold the guides in place.
I’ve created a spreadsheet to help calculate values like the thickness of the piston rod and the length of the crosshead gibs. I am so glad to be building this model in the age of spreadsheets and CAD. How they figured these things out before is difficult to imagine!