She came of the production line in December 1983 according to BMbikes, but she was first registered in February 1986.
So she was built before 1 Jan 1984 and I can stop paying vehicle tax after 1 April 2024.
I don't know what she was doing between February 1986 and 12 December 1991, but she was registered to an owner in Dunfermline in 1991 I bought her from Dunfermline Motorcycles in 1993.