I agree with Duck Ron.  If you add glass/granite plate and some fine grit wet/dry sandpaper and a can of spray adhesive, you'll be in business.  Or, for a few bucks more, add a black Arkansas stone.  They aren't good for heavy removal but to refine an edge they are awesome.  And I don't know what you use with your chisels but a honing guide is a good idea if you don't have one or aren't accomplished at freehand sharpening.  Personally, I don't freehand anything with a straight edge.  Some people can consistently hold the tool at the same angle.  I'm not one of those people.