That just means we don't know the true potential of your chip
But in all seriousness, the i7-920s did OC pretty well (seen many near 4 GHz). It may actually give you some added value over i7-930s since the stepping changed from the 920/940 to the 930/950, and severely impacted overclocking ability.
That would depend on if it's a C0 or D0.
OP, if you have a D0, you'll get higher offers since they tend to go well into the 4GHz clock range. My W3520 did 4.7GHz, while my current 920 only does about 4.4GHz.
Let me know when you decide that you're willing to part everything out.