I've always thought that the title in parentheses was meant to be "begorrah", as all the usual explanations I've seen saying it's meant to be "big horror" in a cockney accent sounded like a load of bollocks, I've never heard anyone use the phrase "big horror".
Bruce confirms this in something that is on the FC website at the moment, and was published in the Fan Club Magazine Issue 117.
“An instrumental! Back in the day people thought that people from Ireland spoke like that. So it was: ‘ah, begorrah!’ So: big ’orra… losfer words. We thought it was funny back in 1984. Whatever, it doesn’t matter!”
Begorrah is bascially a minced oath, i.e. a nonsense phrase used to take the place of a curse, like e.g. gosh, darn etc. in this case it's a susbtitute for the phrase "by god"