No mounting Holes
1-39.25 I will make it 40"
The 44.125 one will need to be 48.125 to have enough to miter so I will make it 49?
The 102.5 would need to be 106.5 to make the miter the max length I can ship is 108 outside of package, it would need to be in two pieces.
I will make it 107 in two pieces.
I will design them to be mitered on site as per your dimension by adjusting the peg spacing and keeping fasteners out of the way at the miter locations.