Stop Start + Problems

[Re-cycled Teanager]

A few months ago the clutch master cylinder shaft broke resulting in the car needing to be towed to my local garage as it was not possible to select a gear. The garage (not a Ford dealership) replaced the master cylinder (with the metal shaft type) so the car was driveable once again. To cut a long story short the following day I noticed that the stop/start, cruise control, speed limiter and hill start assist were not working and the stop/start light permanently shows 'off'. However you still needed to depress the clutch to start the engine. On returning to the garage they said that these faults were not connected with the repair but had checked and there was 'no data being exchanged'. Unfortunately I was moving house the next day and was just glad to have a mobile car!
Time has passed and I now live too far away from the garage to get involved in an argument and in every other respect the car works fine. It has just passed its MOT and the testing station made no mention of the stop/start or other issues so I assume it’s not an MOT requirement?
A couple of months ago the battery had to be replaced but the faults were present before and after replacement so that would seem to rule out the battery.
A fault code reader reports no fault codes so over Christmas I have removed and checked both clutch sensors and their wiring, checked all the plugs and sockets on the body control unit, checked that the sensors operate (by meter) when the pedal is pressed and checked every fuse I can find on the vehicle. In the past the battery has been left disconnected for several days all to no avail.
Short of going to an expensive Ford dealership I’m out of ideas – anybody got any?