Matrixfire Masterkey Remix

Remixed the Matrixfire Masterkey with a few tweaks:

Now uses decorative side panels or picatinny rails!

No more shell cutting on the matrixfire side! The only Magnus cuts required are the cutting the front overhang off the nerf rail and removing the handle.

Supports are only required for the Matrixfire Masterkey_Magnus print

4-40 hardware:

7/8" Screws x3 for main version, x9 for picatinny rails

3/8" Screws x6 for main version

3x 4-40 Brass inserts (McMaster 94459A250)

Presumably M3 hardware would work too but I haven't tested that yet.