Depending on the type of printing, sometimes an erased label can be made visible. First, I would try a UV lamp to look for fluorescence or quenching, as it is the least invasive. Then, because the characteristics of the epoxy may be slightly changed by an imprint, I would try an oxidative etch. That is very much like recovering the serial number on a gun or engine block that has has it ground off.
John
Edit: changed "fluorescent lamp" to "UV lamp" and expanded description.