Two old time Aussie heavyweights. Bell had the experience and probably better boxing skills but Turner was a monster by comparison with power. Each at his best I can't figure this one. Bell stood about 5'10" or 5'11" with 72" reach. Turner was almost 6'3" with a 79" reach. Bell often weighed over 190 lbs. while Turner was usually around 185 or so. Both lost to Jack Howard and Pat Doran, but at different points in time. Turner peaked early 1911 while Bell's prime was likely sometime after 1915. Turner was built along the same lines as Bob Fitzsimmons, while Bell looked more like Jim Jeffries.
I'm leaning towards Turner but Bell was a determined SOB.