1930 Wallis - Massey-Harris - John Deere Vintage AD #1286

This original 9 x 12" magazine ad features Wallis Tractors on one side and John Deere horse-drawn Mowers on the reverse.  The Wallis ad confuses me because it lists Massey-Harris Co on the ad, where on most other Wallis Ads of the same time frame they are listed as being a product of J.I. Case.  Only the true tractor historian will know the answer to this conundrum.