Thanks Brian,
Had a sort'a feeling that the EEPROM might be prime suspect. Checked ChasHyde for replacement, plus a fiver for the soldering job, change from £20.
Customer feels that the next boot sale might provide a working one for a couple of quid.
Suspect that old stuff ain't worth the bother - well at least I have a bus pass - sadly, in the wilds of Norfolk, no busses pass - Chris, the cyclist - well, fends off heart attacks.
PS - shocked to find cust later wanted job done - raised price to £25 as EEPROM with extras like post and packaging (for a SMD pinhead device) brought it to £12.50
Will recycle packaging should I find any - Chris.