Sorry, I cant help with the pole diameter, as we've packed our Nevada away now. However, when we had a pole split, we took it to an independant camping shop where they had a large box of spare poles. We just matched the diameter size up, and it cost us the grand sum of £1! Would it be worth seeing if anyone near you does something similar?
If you can wait until tomorrow I'll check and let you know. The other two pole lengths are made up with sections of different diameters but I can't remember if the back pole is the same.
Alternatively, check your local camping shops as a lot do a pole repair service. Go outdoors charge about £5 to replace the broken section and restring so I imagine other shops will be around the same.
------------- Mar - Milarrochy Bay - 9 days
Apr - Drayton Manor - 1 day
May - Saxdale - 4 days
May - Nantcol - 9 days
July - Weymouth - 1 day
July - Rozel Bay - 14 days
Aug - Corfe Castle - 2 days
Aug - Saxdale - 4 days
Sep - Stratford - 2 days
Oct - Stainforth - 2 days
Dec - Saxdale - 5 days
To be continued.....