And let us know how the experiment turns out!
I haven't built the kit, so I've been picturing your leading edge as if it were a rectangle that stood on its small side with the long side butted up against the ribs. If it's that system, you'd have to remove the covering pretty entirely to sand the airfoil shape into it.
If, instead, your piece of balsa is a square piece that is glued into notches in the ribs, so that a pointy edge is your leading edge, you may be able to sand the covering off just the pointy part, along with the unwanted balsa, and then just wrap a 1" strip around the leading edge. If you're working with something like Monokote, it will blend in very nicely with the original covering. Or you could use a contrasting color as if you intended it as part of the color scheme from the very beginning.