From your picures, it would appear that the lighting circuit is earthed (at least the one photographed). Interesting red/red cable on the switch. Don't remember seeing that on "older" installs.
The cracked sockets should have been noted on the EICR, so should lack of sleeving on the earth wires on that socket.
My guess the MEM board is the original from when the house was built - there may be a manufactore date on it, somewhere.
Hopefully all cable is PVC/PVC so should be good for a while yet, assuming the IR figures are OK (will see from the PDF).
The cracked sockets should have been noted on the EICR, so should lack of sleeving on the earth wires on that socket.
My guess the MEM board is the original from when the house was built - there may be a manufactore date on it, somewhere.
Hopefully all cable is PVC/PVC so should be good for a while yet, assuming the IR figures are OK (will see from the PDF).