Series 7 armchairs. Upholster or refinish?  

Sorry, I don't have any...
Sorry, I don't have any photos of the chairs. This is from the internet.

Is the chair cracked?
Or just the paint?

If the paint is merely crazed,
I would leave it as original,instead of doing major reupholstery.On the other hand,if it's significantly flaking and deteriorating,maybe a good refinish is in order.

Structurally, the chair is...
Structurally, the chair is in great condition. Only the paint is cracked.
Does anyone have any experience refinishing, or upholstering, these chairs?

I refinished one last year...
I refinished one last year and it's really not that hard.
I carefully sanded the paint off by hand to preserve the primer and not to damage the plywood. For the finish I used a wood wax finish from Osmo which is great to work with on a curved surface as it's very gooey. It's also less toxic than paint and proved to be quite resistant to scratches.

Thanks for your...
Thanks for your replies.
If I were to sand the cracked paint, I would be down to the plywood in some areas. I suppose that a light sanding would improve a majority of the cracking.