Hi Giles,
I've just hauled out the ole and it's 80mm diameter but the tube is only 3.9m long. Neither of the end fittings have their spring loaded plungers, but I may have some old ones of those somewhere - just have to remember where!
The old pole came with Wild Thyme, but we replaced it with a second hand one the right size off a Moody 41. J for WT is 5.03m and her beam is 4.07 m so the old pole only stuck 1.9 m over the side, the J length one sticks out 3m.
Hoping to meet up with you this weekend.
Peter.