Playing with radio transmitters

Late last year I bought a new transmitter, basically because the old one is pretty old, heavy and dented. It seemed a shame to throw the old one out, and knowing many have "customized" their transmitters I thought I would have a go.

So the case was opened and investigations began. There are two circuit boards. presumably one that provides power and the aerial connection, and the other does all the encoding. Having taken the pots out of the joysticks and removed all the trimmers from the casing, I checked that it all still worked, and labelled up each pot with the channel number.

Then it was time to go at it with some cutters and try replacing the pots. The idea is this:
The pan controlled doesn't really need any fine control, it just needs to be capable of being swithed clickwise, anti-clockwise or stopped. This should be achievable with a switch provided I can find the sweet spot on the pot where the servo changes direction.
The tilt servo I'd like to contorl with a slider rather than a rotating pot.
The shutter should be controllable with a simple push switch.

I've checked the pots and they are all marked as 5K. Time is fairly short, but I'll let you know how I progress.