Here's some info on the F16A Block10 Gear handle. I've taken measurements of an original F16 handle, with special thanks to L. Sleegers who is the owner of it!

The next .GIF image is a link to a scale 1:1 drawing of the actual gear handle. They meay be off 1 or 2 mm here and there and some curved surfaces have been simplified. Keep in mind that the circular shape at the end/beginning of the handle is more an estimate guess, as there was no way for me to tell how things are shaped around the 'turning axis' (it was invisible inside the 'handle-box'). Under the .GIF you can find some 'real' pictures of the gearhandle from different sides. Notice that on the pictures the lighted 'knop' that's at the end is not shown. The knob-outline in the drawing is more of an estimated guess!!
 
 

All pictures courtesy of L. Sleegers (Helvoirt, NL)
 

Here's a way to add some tension to the movement of the handle, as well as locking it in the endposition 1 = A pin connected to the gear handle 2 = A tension-spring  3 = Carved out shape in the gearhandle  4 = pin that moves in the carved out shape and is attached to a fixed part independently of the gearhandle  In picture A the handle is in the middle position. In picture B it is in the up position. In picture B the spring has shortened in length because the two pins have moved closer to eachother. This is how the spring keeps the handle locked in this position.  The same thing applies to the handle being in the down position... The spring also makes for some 'tension' in the movement, 'forcing' it to the end positions.