Welcome to the forum.
What area are you in?
I couldnt think of having seen the Registration Number about, i usually pay attention to Defenders & Reg numbers, so i looked it up.
Is it Grey as it comes up on the DVLA site?
Says 'Manufactured 1987',
and 'first registered 1992'
Is that when you think it got Registered in NI, 1992 ?
george