That's awesome you want to work on it. I wish you luck!
I would also say the steering lock isn't worth it. Just get a beefy bike or moto lock for it. Someone could always throw it in their truck, so that steering lock doesn't do anything, you have to lock it to something.
The other parts can all be aftermarket/generic. I wouldn't suggest that you try to keep it all original, unless it's worthwhile for you somehow.