Sorry to say, but it is a fake, or something rather dodgy. It dosen't seem to exist. Nor by the SL, nor by the model, nor by the FPO number.
What does the BIOS and windows say the CPU is?
The BIOS says it's an Intel core 2 quad Q9500. The Intel Processor Identification Utility says it's an Intel Core 2 Quad Q9500S @2.83Ghz, system bus 1333Mhz, L2 cache 6M. CPU-Z says it's Intel Core 2 Quad Q9500S, yorkfield, L2 6M, stepping A, revision R0. It's still running great but it's strange the sSpec is no where.