Hi Paul,
I would like to add something to the other comments, Perthshire made the
PP5 model (Mahoney p.81) and this also has the hollow ground base (after 1972 until 1995) and
it is also distinguished by the translucent ground (while PP2 always has opaque grounds)-
For the P signature in PP 2 Mahoney says weights before 1978 are unsigned, weights made since 1978 have a center "P".
The PP 5 can have a very similar cane layout as PP2 does, but the translucent ground with yours point
at PP 5 also, I had do "move" one unsigned from PP2 to PP 5 on behalf of the translucent ground,
kind regards e.j.m.