There is, or was, a Nimrod MR.2 in 1/72.
It was a vac form kit from the UK and if my memory serves me correctly, it was made by Aeroclub.
It was about five years ago that I last saw it advertized. As you are in the UK, you may want to contact Hannants if you haven't done so already. The kit may still be on some retailer's shelf.
Good luck