I built one of these chairs in a 4-day course I took with John Robinson at his shop north of Toronto in 2006. This type of Windsor chair is called a “Continuous Arm Chair”.
The chair was finished using milk paint, topped off with 3 coats of an oil-varnish mixture. This is the traditional method of finishing Windsor chairs. I purchased the milk paint from Homestead House in Toronto. I first brushed on 2 coats of “Fort York Red”, and then 2 coats of “Coal Black”. After the second coat of black paint dried, I distressed it a bit with some sandpaper in places where paint would normally wear if you sat on the chair a lot. This exposed some red paint under the black, and makes the chair look more like an antique. I then rubbed on 3 coats of an oil-varnish mixture (equal parts of linseed oil, tung oil and gloss spar varnish), waiting 1 day between coats for it to dry.