Info needed: Trouble removing Ferret rear vision flap hinge pins

[Robin Ross]

I am trying to remove the rear vision flaps on my 1954 Daimler Ferret Mk1, so I can get into the nooks and crannies and clean and paint the inside.

I have three of the four pins out; however I am having trouble freeing up the upper outside pin. I have tried WD-40, and tapping it with a hammer; however, it doe not seem to want to budge.

I want to see if anyone happens to know a trick to removing this that I may not know about before I try the rougher methods of; heat the hinge with a torch, or grinding the ends off and driving it out. I would rather not have to track down, or make, a replacement.