And it is not Pearl (she says looking at her Kobo WiFi and Kobo original side-by-side). Seriously, the information on Koboreader.com is accurate. If you want to try the FCC filings use this reference number: NOIKBN647. I didn't see anything useful. I did find this filing
by Netronix which appears to be for several different devices, including Kobo WiFi, but it didn't say much.