I think you need to go back to do it in Sichuan, because only the original
police office you first register your "HuKou" had the copy of your original
birth certificate. Ask your parents to remember where they first register
your "HuKou" after your birth, and go there to have your police certified
copy. Then use this copy to notary agency to have it notarized.
It is birth certificate, it has nothing to do with your current "HuKou"
location. Just a matter of who can proof your place and date of birth.