Logic Masters Deutschland e.V.

Previous Dutch Flat Mate Puzzles
This has been a weekly series since '18 Oct 23'. Here is a spreadsheet link for all the previous puzzles in the series, which also has a few teasers for upcoming constraints/guest setters in the series (subject to change).
This alternative link offers a limited LMD search for Dutch Flat Mates.

Special Thanks
Richard used Assorted Sandwiches in his Advent series, and that was my gentle, yet delightful, introduction to this constraint.

To play the puzzle, please click the image:

Initial Setter Difficulty: 2.5 / 5

Normal Sudoku rules apply
Place the digits 1-9 so that they do not repeat in any row, column, or 3x3 box.

Dutch Flats
Every 5 in the grid must have a '1' directly above it or a '9' directly below it. It may have both, but it doesn't need both.

Assorted Sandwiches
Clues outside the grid indicate the presence of a sandwich in the corresponding row or column. A sandwich has two digits that act as its boundaries. The clue is the sum of all the digits between those boundaries. The boundaries are the two individual digits of the clue, in any order; for example 31 outside the grid would mean that the sum of the digits placed between the digit 1 and the digit 3 (order is not given) is 31.

Hint to start

29 is one of the most forcing clues in this constraint: 29 + 2 + 9 = 40
Therefore only digits with value 5 appear outside the crusts.
Column 4 is very fruitful after some consideration of all 29 crusts; and happy 5s will guide you to the intended solve path.

Guest Setter
Next week Marty Sears makes a very welcome return to the series, and maybe you can help him with his bad hair day?