This is a replica of a B8 Flight Stick used in many helicopters and fighter jets. The model has holes cut out to place m10x1.25 nuts which is the thread size used for many shift knobs. I did my best to recreate the shape of the knob based on many photographs.
I have included the Solidworks files if you are interested in modifying them to fit your specific parts.
The buttons were found at a local electronics shop and can be found here: http://tinyurl.com/pec2u3o . The joystick mechanism was a salvaged piece found at my local makerspace, the only marking on it is "Tomy". The trigger pin is a hardened 1/8" steel rod from the optical drive of a PS3 cut down to 1.7" long. I found a spring to use for the trigger mechanism at the makerspace, its dimensions are 1.4" x 3.7". I used the head of a brass nail as the brass circle on the directional knob, to get it into place requires some extra sanding and drilling.
After printing all the parts at 70% infill, I inserted the nuts, glued the two halves together using methalyne chloride and fused the seam using a soldering iron with a flat tip. I then sanded all the parts, and painted the body a gloss black. The joystick and buttons were press fit in. The direction knob was heated with a smd rework station and then press fit onto the joystick, leaving a 1/8" gap so that the knob could move properly.