I have a very antique Randall 103 central heating timer, which decided not
to switch on this morning - so perhaps the time has come to improve on it.
Trouble is, I can find to way to remove it from the wall. I've managed to
unscrew the cover at the bottom where all the wires come in. Of course I
could just smash it - but as I may not be able to get a replacement yet I'd
rather not do that. Has anyone any knowledge of how these come apart?

TIA

Keith