I managed to lift the cover of the battery back to access the battery, and got a 3v reading. So I am now assuming the battery is fine. However, I did remove the whole battery pack from the board earlier. Hopefully this hasn't killed anything, but if it has its my own fault (live and learn etc)...
The condition of the board is excellent, the LED to indicate operation comes on, but nothing else happens. Is it likely to be dead battery? It was working before it spent a long time in storage.
The dead battery society website says replace the battery with a 68000 and replace a few EPROMs. But...