You're probably going to want something more aggressive than 120. If you're doing It by hand maybe get some 36 or 60 grit wet/dry or ceramic sandpaper and make some sanding sticks from scrap wood/metalCheers, I don't have a belt sander but my diamond file just turned up. 120 and 300 grit. Then I have diamond stones going 360, 600,1200 so I think I'll do the reshaping with the 120 then work my way up til it looks like the standard finish.
Plan is to make the blade shape more like my favourite shape, the BRK bushcrafter.