Omega/DPK sneaky petes don't usually have the flared butt-caps. Check out the ones on Erik Lee's website. It would be tough to authenticate, as Bender sneaky petes pretty much look the same and the pin's on his SP's aren't marked like his usual cues. I have seen some Bender SP's with hoppe rings. Authenticity could go either way because of these details, but the values would pretty much be the same for an Omega/DPK SP or Bender SP.
The story goes that during Omega/DPK's business days, only about 10 sneaky pete's were made. I've seen over a dozen in person alone, tough to say if it is an Omega/DPK or Bender. And both sport variations of the 3/8-14 pin. Some pins are beveled, others aren't. Some pins have holes on the top, some don't. Some pins are highly polished, others have a raw matte steel look to them.