B sickle mower

My B belly mower drive pulley is 10" outside diameter (actually more like 10-1/8"). I don't think you have to have a special one fabricated for big $$$. You could use a standard pulley from Browning. The belt is a "C" section belt -- I use a C51 belt from Gates. The browning pulleys use replaceable split taper bushings with different available bores. You would get the bushing to match your PTO shaft. That's either the 1-1/8" 6 spline or the 1-3/8" 6 spline depending on year. Such a pulley would obviously look different than original and would not have the adjustable pitch diameter feature. But if you are interested in function over appearance, that shouldn't make any difference. I use my mower every year to mow about 10 acres and have never (in 30 years) found the need to change the sickle speed by re-shiming the drive and driven pulleys. About any local dealer of power transmission equipment should be able to get you Browning stuff.

Rod