There are five control cables for the MGA dash controls, Choke, Starter, and three heater control cables. The Choke and Starter cables are pull only and have twisted cable center wires. The heater control cables are all push/pull function with solid steel center wires.

The temperature control cable (heat slider lever to water valve) is the easiest to change, as it has plain ends for the wire and outer jacket at both ends. You can pick up a Universal Choke Control cable at any auto parts store, cut it to the length you need, and screw the cable ends in place using the stock MGA attachment hardware.

The rest of the control cables are more a job for a masochist, as the center wire is crimped into a steel pull rod. You can pull the shaft and the core wire out of the sheath. The problem then is how to "un-crimp" the back end of the rod where it is smashed down onto the wire. You might cut the wire off flush with end of the rod, then drill out the wire (and the crimp spot). Then slip in a new wire and crimp or solder it in place.

Be aware that the choke cable assembly includes a sort of detent for the "twist to lock" function. There is a groove in one side of the rod, and a small spring loaded steel ball that rides in the groove for upright orientation of the knob. When you twist the knob the spring loaded ball serves as a mechanical friction brake to hold the shaft in the extended position. If you pull the shaft and wire all the way out of the sheath, you may lose the little steel ball. It is best to figure out in advance how the ball detent is assembled and disassemble it before you pull out the rod, and reassemble it after the rod is back in place.