Sketches done on site are often hard to follow. Normally, I'd make a fair copy when I returned home but, in this case, I haven't found a later copy, so here is the original version from 2nd September 1964.
(Click on the sketch to enlarge)
T - Tubular post
W - Wooden post
Penzance station remains in operation.
For details of what remained in 2005, refer to 'Railway Track Diagrams' Book 3: Western', Fourth Edition, published by Trackmaps (ISBN: 0-9549866-1-X). The First Edition of this book was published by Quail in 1989.