I kinda understand Ed's point, though he of course has ruined more guns than I'll ever see.
As a seller, the sort of buyer who shows up with a kit like that would alert me to two things:
1) He's gonna take a lot of time looking at the gun, and might even start disassembling it. Every time a gun is 'handled' it sees the potential for damage. Do I want that?
2) Chances are he's a pain in the ass to deal with - not only in terms of 'what is the gun' but also in terms of the commercial side of things.
I'd be tempted to tell him to take a hike, preferring to sell it to someone less fussy.
Then again, if I were selling a $1000+ double, I'd have already recorded the important dimensions which seems impossible for sellers to do....
