Hmm... It would be an interesting wood-carving project.
I reckon that you have the original kukri with you? Because you should try to train with a weapon that is as close to the one you intend to regularly wear.
As a self-defense weapon, I am not so sure about a kukri. As a weapon, of course it is powerful. However, in a self-defence case, you most likely are in an everyday situation when you are suddenly attacked. You'd be better off with a concealable, quickly-drawn, small weapon like a baton or pepper spray. Than run away.
That's not even getting knife-laws involved. Check them. You don't want the police to confiscate your $150+ handmade kukri, now do you?
Unless you have your own lands you regularly walk trough or live in very rural areas where such tools or similar tools are common, I don't see a kukri being an ideal choice. You are fairly unlikely to get mugged while hiking.
Now, on the wooden kukri thing:
One way you can do this if you have the time and whatnot, is the following: take to thick planks. Mind the grain and try to pick ones that have a grain that is not parallel to the cutting edge.
Cut out the kukri's shape on both planks. Hollow out the inside as much as you dare. Now, using small lead or iron weights and glue, you can make a wooden kukri that has the same weight distribution and balance as your real one. You might want to save on glue by using sawdust as a filler.
As a finish, you can wrap the whole thing up in tape, parallel to the cutting edge. This should be done thickly, to help keep the practice kukri together. You should pad the "cutting" edge with leather or something equally though, to have it stay longer.
Eventually though, you should practice with your "real" kukri on wood to know how the cutting edge works.
