OK they are 30s the wheels and spacers where fitted by the previous owner, the aalignment was done by Nissan ( have a receipt ) and subsequently checked by my independant when I bought the car, in the history that came with the car there is no mention of adjustable control arms etc
Fyi the rolling radius is pretty much spot on as the speedo is within the excepted misread ie is reading 3mph higher than actual as verified on a rolling road using dot approved equipment.
Thanks for your input.