BaldwinM
I can only offer my recent experience of renewing an outdated UK PPL, although it was much further outdated than yours (1968).
1) I was informed that the UK would issue a JAA PPL, not a UK one,
2) I had to pass ALL examinations, including the R/T licence.
The CAA have a GID (18?) on this, which covers the case of less than 5 years, 5 to 10 years and more than 10 years out of date.
My recall of the more than 10 years is:
a) mimimum of 10 hours flying,
b) including a minimum of 4 hours solo, which can include the qualifying x-country
c) 4 hours of x-country, including a qualifying solo x-country with 2 land-aways and mimimum distance (150km?)
d) at least 2 hours stall/spin awareness
e) instrument training to the satisfaction of the CFI
f) skills test
In the end I did 25 hours, but that was partly due to the problem of not realising my medically prescribed glasses (to conform to JAA standards) was preventing me from seeing the runway at the flare