Good question Ron. Your proposed path would work great for most folks' needs for regular sized sheaves. I usually work with small belt grooves that require sharp pointed tools & a parting tool wouldn't work.
The one I'm working with now is a Gates Poly-V which has a 62 deg angle on the big one & 60 deg on the small one. So I'm using a DCMT (55 deg) insert. The other one is a Gates Micro-V which has a 40 deg angle & I would use a 35 deg insert (I forget the insert spec).
The quandary I'm in now is that I'm trying to make a large (relative to my little 8" lathes) sheave in cast iron which requires mucho torque & very slow spindle speed. Anybody wanna guess what I'm making? A slow-speed, hi-torque reduction pulley system for my lathe! 'Ol Joe Heller is smiling in his grave 'cuz Catch 22 applies here for sure.
When I finally got through the I'm-too-ignant-to-use-Dolphin barrier about 11:00 PM last night, the spindle stalled at the low speeds necessary to make the cuts, even with what I thought were shallow cuts & slow feeds.
So, I've got to either rig up a temporary spindle drive, (maybe using my big 1/2" drill but it's still too fast) reduce the D.O.C & feed even more & drink coffee while it runs for 30 or 45 minutes or just go to the manual lathe & hand-crank it with a 60 deg insert plunged straight in & not worry about the 62 deg thing. Probably the latter. I've spent way too much time with the silly thing: