As noted,, if the mainframe states "Vaquero" then you are on the heavier, (Blackhawk) frame. If it says "New Vaquero" then it's on the smaller frame,, meant for milder loads. The serial number is an excellent way to get info as well.
But for the model info to decipher the codes; the RENE Guide is invaluable. I THINK you may have mis-typed your info above. A Vaquero such as RBNV-455, (not RBHV) would be a "blue Ruger Bisley New model Vaquero with color case hardned frame. in 45 Colt cal with a 5-1/2" barrel." Notice the first 6 words in that description,, how 4 of them are capatilized? That's the info that describes your gun.
If that is correct,, you have a Vaquero,, NOT a New Vaquero,, and it can handle the heavy loads.
BTW; the price was very fair.