P is very early.
If the odometer is analogue its not TAPE.
If its on a private reg and has digital odometer then it needs to be between late 99 and late 2000.
Chassis number prior to the numbers of XJ, XU, XM, XP or all Y except YS and YT.
If the you have 1J12345 ie. a 1 or 2 to the left of the last letter its too new.
Probably should consult the proper documentation for chassis number breakpoints.