Perfect Rectangle Puzzle 5620x7526

A rectangle is called simple perfect if it can be filled completely with squares of different integer side lengths. This nice mathematical feature can obviously be turned into a puzzle.
The smallest simple perfect rectangles consist of nine pieces, one can be found here: https://www.thingiverse.com/thing:2367965. To make things more complicated, the perfect rectangle presented here consists of 23 pieces. Moreover, this perfect rectangle has the best ratio of the side lengths of the smallest compared to the largest piece, so all pieces are easy to handle. As a consequence, some squares have very similar size (601 and 610, for instance, i.e. the difference is 9*.02mm=.18mm). In these cases you might use the side length printed onto the pieces to check correct fit.
The puzzle comes with a tray and the square pieces. They have their side length printed of one side. If the puzzle is solved you can turn over all pieces to get an optically pleasing flat surface.
If you can read German: Meh