What was the item number?
You can't tell from just that pic, though, whether it was a BS or rubber dome board.
That said, I don't know if the rubber dome boards in the UK were the same way, but the rubber dome boards here were all made by Lexmark, and all had fixed cables. That board has the detachable cable and blue logo - which, in the US, would mean a board made in 1993 or 1994 by IBM.
(Using clickykeyboards for reference, the first Lexmark 52G9658 was made 1993-02-09, and the last 1391401 (but made by Lexmark, confusingly) was made approximately 1994-02-22. The last IBM 1391401 was made somewhere between 1993-05-25 and 1993-08-03 - I'm typing this on an IBM 1391401 made 1993-06-03.)