Heavy old wheel there!
If your lathe is big enough to hold the stock in the jaws with no center I would just chuck up the stock, turn the OD parallel to the largest size, face it off, bore the hub for axle clearance, turn the side features and bearing recess, then cut it off in my bandsaw, clock up the OD in my 4-jaw and repeat for the other side.
Finally hold it by a bearing recess, dial in the OD and turn the crown.
If you can't hold the stock in your lathe I would cut off the stock 1/2" over-length and do the same except for turning the length of the wheel to size in the process.
Peter - novice home machinist, modern motorcycle enthusiast.
Denford Viceroy 280 Synchro (11 x 24)
Herbert 0V adapted to R8 by 'Sir John'.
Monarch 10EE 1942