Are there any good ideas out here for stretching an '09 Road King gas tank for a bagger project?

1. I have seen the glue on covers. My body shop guy says he can do them, but doesn't like them.

2. We can weld and fab the stretch.

3. Convert a non road king tank by adding a fuel bung.

4. I can't find an aftermarket option like the non road king touring bikes have.