Parametric Rietveld Steltman chair

I'm going to build a Rietveld Steltman chair and found a link with a good description with the original dimensions (link: see below). Don't print this model, it is not intended for it (however, you can easily change it).
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In the original they use 44mm thick wood, but I have spare wood of 25mm thickness. I wanted to fiddle around with dimensions and see how it looks like, before building it all. So I created a parametric openscad version of the chair. Provide total width, total height, seati