Jet impeller sharpening

[ptarmigan]

I pulled my impeller yesterday so I can clean it up. I plan on buying a new one and keeping this one as a spare (figured I should always have one). Question I have is how to get this back in to shape? The diagram on outboardjets website seems to show the bottom side of the blade has a bevel (gentle curve in their words) to it, whereas my impeller certainly seems to be beveled on the topside of the blade (tapering down to the leading edge) and flat on the bottom. I don't want to screw it up any more than I have but I want to fix it. Any good tips? BTW this is a aluminum 6 1/8" impeller used on a 50/35 jet.

Link to outboardjets diagram http://www.outboardjets.com/pdfs/IMPELLERSHARPENING.pdf

Pics of all three blade edges.

[Yukoner]

I seem to recall a thread where Grant Wooldridge mentioned they had better results with impellers being sharpened opposite to the OBJ diagram.
I have run them both ways and never really noticed much difference if any.
While yours is chewed up a tad, that won't take much to get it back in shape, just get a big old Aluminum casting file or similar course file. Won't take long.