Got a Parker 45 recently and it had a broken nib, so last Sunday I figured that I might grind it like there's no tomorrow. After all, I had nothing to lose. (I was in a grinding mood anyway, as I sharpened three knives earlier that day.)
Started with a diamond knife sharpener I had lying around, to shape the nib, and then followed with the entire gamut of micromesh. the most challenging part was to get a flat section out of a concave object (remember, the tip of the nib was missing).
The pictures show the result of each step, first with the sharpener and then as I polished with the micromesh (I love this stuff and hate that I barely have any time to indulge in this).
I'm not sure that I have a pen smoother than this one now. After narrowing the tip of the nib as much as possible, I turned it into a stub or italic or whatever that's called. Symmetry could be a bit better, but it works, so I ain't touching it further.
And without further ado, the pictures!