Spoke to an auto electronics dealer, not MB but better because he told me what I needed to know rather than entice me in to spend lots of money.
I checked the fuses already in to make sure they were fully home.
Then checked the spaces against the fuse map and found one missing that had wires going to that slot. 21, 22, 32, 33 were showing under central locking but only 21 and 22 were in place.
Many of the listed fuses were missing but checking revealed that those positions were not wired anyway so this must have been one of the many options.
The sparky told me that once keys were synchronised to the car they stay that way.
If the car battery went flat you would not expect to have to program everything again would you?
The fuse missing was 8 and this position coincides with the hinged boot liner tab so I must have knocked it out trying to fit the fuse flap in the boot.
As for the roof if fuse 9 is removed the inside roof does not work nor does the relay come in.
When fitted the relay comes in, but drops out after a few seconds, due to the motor load detection, i.e. the relay is energised and current fed to the roof motor but being stiff with old grease it loads the motor which is detected so the relay drops out preventing the burning of the armature.
The only way to open the roof it to push the button and lift / push the back part of the window to give it some assistance, then when open re-grease .
All done !