Is this a rather short chair? When I view the seat and bottom of the rocker it reminds me of the "Fireplace Rocker" (later called a sewing rocker) from the early 1900's that was "hearth height" to keep one warm. I agree that the arms just aren't the same "style" as I would expect to go with the back woodwork of the chair (More mission style) - but it looks like it has aged with the chair (from what I can see in the pictures.)
I'll be seeing Sam (Houston that is) next week on my way to my daughter's. He is so doggone out of place standing along the highway! (stands 70' tall) I don't know as I would call him a furniture expert tho'!
You are driving south on Hwy 45 and you just pass the Texas State Penitentiary of Huntsville (Prison for those of you that don't know the nicer sounding term) then BAM (stealing from jacon4) There is Sam standing in the trees on the side of the highway all by himself! Nothing else around! He is huge!