Adjustment
With the FreeCAD document you should be able to adjust the length, hight and screw clearance. You can also choose between D and C cell models.
You can adjust the values in spreadsheet and hit enter to update the model.
Hardware
I used two 4x30mm screws to mount.
Notes
The print shown in the image in the 60x20mm size for the D cell maglite.
It should also be able to hold up any maglite as mine is the 6 D cell version and I've not had any issues with mine and its only printed in cheap PLA.