Hello,
Unfortunately we are not providing STL files and the part which mainly changes the size is from metal.
But you can purchase either Metal base or longer rails, but it could cause another problem with paracords which are made in specific measurements depending on large or medium keypad.
Meaning that if you change lets say metal base from medium to Large paracords and wires within will be very tightened and adjusting tower at furthest wouldn't be possible.