Factory Two Tone Blackhawks?

Has Ruger ever produced two tone new model blackhawks? I have a guy right now wanting to trade me a 357 new model blackhawk that he purchased used that has the 6" barrel and a stainless looking cylinder and ejector tube. I have only seen a phone pic of it. The grips are the black plastic Ruger grips.

Are these factory Ruger as part of a special run or exclusive and how do I tell if it was factory? I can not find any info online for this.

Thanks!

They did do an odd run of 327 mag,, NOT 357 mag guns that were two toned. But in this case I think that the gun in question is NOT factory. At least from my faded memory about New Models. Someone else may know better.

No not factory. If it's a Flat Top NM Blackhawk, the mid-size frame, (3 digit serial # prefix), no stainless cylinders have ever been made by Ruger, so you'll want to confirm it's not carbon steel just polished out.

Or if a large frame standard NM Blackhawk, (2 digit serial # prefix), there were stainless 357 cylinders made.