==== RULES ====
Diagonal Sudoku rules apply : fill the grid with digits 1 to 9 appearing each exactly once in every row, column and 3x3 box and on the marked diagonal.
Palindromes : along grey lines, digits must read as the same sequence from both ends.
==== ACKNOWLEDGEMENTS ====
Special thanks go to SSGranor and Philipp Huber for testing !
Solution code: Digits from Row 3 (left to right) and then Column 5 (top to bottom). 18 digits total, no space character.