The Lighthouse was lit up in December 2001 - only 14 years ago.
So, where did they get 42 years from?
Well, the source is the Liverpool Echo which got their quote from the Council, but the answer may be in the small print as it does say the project "aims to restore the lights at the top of the lighthouse in their original form." It also refers to it being decommissioned in 1973 - hence the 42 years.
I seem to remember there being a problem with Trafalgar House, or some official body, when the idea of re-lighting the lamp was suggested in the past - probably about the time of the Tall Ships event.
The Echo link will also take you to 13 great pictures of the Lighthouse.
I took the one below on Jan 1st 2002.
Description: New Brighton Lighthouse lit up for Xmas & New Year 2001/2.