What you will need
* 1mm styrene
* 0.4mm styrene
* 0.8mm styrene rod
* plastic cement
* Xacto knife
* sandpaper

Step 1.
I started with this. 1mm styrene cut into a shape like this, and 0.8mm rod cut into three pieces ( rods can vary in length depending on preferences) cement in place as shown in steps 2-4

Step 2.

Step 3.

Step 4. Shifter stick should look something like this.

Step 5. I had to improvise a bit here. 1mm styrene cut into two 1.5mm boxes.

Step 6. Cement boxes together to make a 1.5x2mm box. Smooth with sandpaper if necessary

Step 7. Using 0.4mm styrene make a 6x4mm rectangle. Cement 1.5x2mm box to the 6x4mm rectangle offset towards the front. Cement shifter stick to box

Step 8. Cut 0.4mm styrene into these three shapes, and cement in place as shown in steps 9-11

Step 9.

Step 10.

Step 11. All Finish