Wanted to avoid joining bits together so got a 19mm flooring sheet 3.6m long.
Spent a bit of time re-establishing routines and marked out work, checked a number of times then cut out with a 6" circular saw, noting after the first two cuts it was not set at 90 degrees. Grrr.
Marked up the shelf lines, and there seems to be a discrepancy with the height of the tips. Checked all the measurements with the drawings and text, and all are correct.
Plan to trial assemble bits and see if I can figure it out.
Used some 19mm square hardwood scraps to make most of the "one inch" supports needed later.