Looking for tips on concealing damage to wooden chair legs?

Try this method: apply with a rag and quickly wipe it off to avoid over-darkening. If it’s too light, you can always add more for a deeper shade. Those chairs are gorgeous! You could have a professional apply a coat of varnish after fixing the stains, but it’s not absolutely necessary. Old English provides some protection by partially sealing it from moisture. However, your varnish is peeling and will likely need frequent touch-ups.