Ahhhhhhhhhh! Found the menu by accident, then found that the hack posted here is not quite right for the JMB... here`s the solution that works for mine:
REGION CODE & COLOUR SETTINGS CHANGES:
Hold "STOP", "OPEN/CLOSE", "SKIP FWD" while powering on. The hidden menu will appear.
OTHER CHANGES (NO NEED TO ACCESS):
If you hold "STOP", "OPEN/CLOSE", "SKIP BACKWARDS" while powering on, an INITIALIZE TYPE menu appears, which should NOT be changed from "1"
Also, if you access the INITIALIZE TYPE menu by accident, you will need to re-enter your region code in the region code/colour settings changes section above.