Are you going to strip them completely?

We can if it's needed. Certainly much of it needs sanding.

A couple of professional furniture refinishers on Houzz give excellent advice. I hope they chime in.

I think you'd get a more uniform finish starting with a clean slate. But you could try overcoating some small part with a restoring finish or tinted varnish to see how it looks. Ask at a good paint store for their recommendations. Check the finish fiirst to see if it dissolves in paint thinner.

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Of course, they would be awesome painted. What is it with men and not painting wood? They are indeed great chairs.