I don't think that there was such a requirement under the CAA PPL. Its a long time since I did my GFT (1993) for a CAA PPL, but I don't recall ever having to do a spiral dive recovery on instruments, and there was no radio nav at all in the CAA PPL. IIRC the only instrument flying we had to do was a level 180 degree turn
I only got to do spiral dive recoveries on instruments when I did the IMC rating a few years later.