So to be polite it could be said it is work attributed to RJK or in the style of RJK. That aside it comes down to evaluation of the amount, extent and quality of work done. Since I assume no record or card exists for this gun we are on our own determining what it is and where it came from. Kind of like a legend gun. Legend is that this gun came from here or was made by him for someone else. I guess for 100+K is should have a good legend or the new owner has the right to invent his own legend.