So easy to sharpen, one way is to use the GD to drill a bushing, set the tail end on the tailstock of a TC grinder and the front end in the bushing. set finger below center to get a 10 to 13* clearance, grind. but not to take away the front center if it is still there. With the cutting lip ground roll/butterfly around the rest of the point.
320 wheel or finer is best.
Good to have a double point finger so the Higher point rests on the tool OD in order to stabilize the finger location (lower point)...so grinding pressure does not waver the position.
Some grinder hands grind a secondary first and then just tickle the cutting edge corner primary at 12* soo getting a better finish.