Oh, I don't know how I missed this but I have not even taken into account the 'collectors perspective' on this. Say you take an old knife apart and mix parts. Unless it is redone with original parts from the same model or original replacement parts from the manufacturer (unlikely) and even then only if its done in such a way as to prevent even a good appraiser from knowing you were 'in there' you can and probably will take away any collector appeal for the knife at best or at the worst create a 'fake' as they call them in collector circles and see selling as originals on ebay and other sources. This is a sticky area and some may end up paying high dollar for a 'repaired fake' down the road unknowing so if that is anything worth keeping in mind you may want to dwell on that idea for a while. What I'm saying is that you can't take a Kabar trapper slip joint and stick a Kabar Stockman pattern main blade in there and call it anything worth showing or displaying as a collector worthy piece. At that point its a user and nothing more.
When folks call Kabar for an old knife often times Kabar hands them my information to get in touch with me. I've actually had people get mad at me on the phone because they simply cannot understand why I can't just make up a replacement blade and stick it in an old Dog Head Kabar they broke the blade on. Fack is its worth more as it is than what it would be if I touched it in that case. Contrary to popular belief by some, this bothers me to do that and I wouldn't. There is no accounting for what would happen to that knife once the person asking me to do it passed away. Years from now it could end up being one sold to someone as an original and some don't seem to get it. Anyway, its not that I have not modified users still being made but truth be told I try whenever possible to do things in such a way as to allow the owner of the folder to always be able to put it back together the way it was shipped to them but even this is not full proof. There is no telling if that original liner and lock or anything else would stay with the knife. So again its tricky business to deal with, particularly with collector pieces. I also make sure my "STR" is somewhere visible on the knife showing it was done by me and that I am the 'guilty party' so there is no mistake that its not original. This is not often the case though and it still does not justify the act of modification from the stand point of most collectors. Just FYI.
STR