Yes I did consider this, but these are 2mm x 23mm pins as opposed to those gateposts, and each hinge has 7 pins
OK I can get stainless 2 x 24 and grind a bit off or 2 x 22 which would work fine.
The only minor issues is being able to drive or press out the old ones - without damaging the knuckles - and then pressing in the new ones.
Given the relationship between pin and hinge has become closer over the years that looks like a bit of a tall order for a Black and Decker, hammer, nail and mole grips.
If you've got the kit it possibly can be done but I no longer have access to those sort of tools sadly.