The main risk is if they scrutinized you for something else. Customs agents can barely keep tabs on illicit traffic of cultural treasures; to an untrained eye heirloom art looks like mere junk. I personally heard one first-hand account, around 1993, of someone who shipped a bag full of books to China. The local postman knew how to tie a special knot that came undone by pulling the rope in a peculiar way. When the books arrived he could verify that no one opened the bag...via knot-theory message authentication. The only thing I ever had intercepted by Chinese customs was an obsolete computer (I needed an old-style ISA slot) at a time when they were cracking down on improper recyclers.