It's very difficult to estimate the value of a modified gun (if in fact it has been modified). It's going to be valued as a shooter, not a collectible, and further, being chambered in .22 WRF will definitely not be attractive to anyone wishing to use it. That ammo is costly and difficult to find (although I think someone is now loading it). I don't think I'd want it at any price, just a personal opinion. I'd suspect that anyone interested in it would want to rechamber the cylinder to .22 WMR. NOW, if it came from the factory chambered for .22 WRF, that's a totally different story.