I'd make it 2"-2 1/4" at the fades, taper it down to 3/8" wide at the nocks. Leave it the full 3/4" thick under the fades/riser, and make your thickness start at about 5/8" thick at the fades. This will give you a 1/8" thicker portion to glue your riser to, hopefully keep it from popping off. You might try glueing on a riser made up of a few thin pieces instead of one thick one, building it up to 1 1/2" or so.