Perfect Square Puzzle 112x112

A square is called perfect squared square if it can be filled completely with squares of different integer side length. This nice mathematical feature can obviously be turned into a puzzle.
The smallest perfect squared square has side length 112 and consists of 21 squares. This smallest squared square was found by A. J. W. Duijvestijn in 1978, see https://en.wikipedia.org/wiki/Squaring_the_square.

The puzzle comes with a tray and the square pieces. Their side length is printed on one side (except for the tiny sqare with side length 2). If the puzzle is solved you can turn over all pieces to get an optically pleasing flat surface.
If you can read German: Mehr Informationen gibt es in https://welt-der-geduldspiele.blogspot.com/search?q=3D-Druck

Printing instructions:
The pieces are printed in three colors for optical reasons only.
The printing size of the puzzle is 1.5mm per unit.
I printed the puzzle in PLA at .1mm layer height.

Puzzle difficulty: The fact that the square