Superb 08 Sight Wrench...

[ViggoG]

John D and GT,
The subject of marring the barrel could be corrected by controlling the finish if the interior of the Barrel Band and Post portions of the tool.
These should be highly polished (and need not be hardened) so that no scratching will occur. .
The flat end of the "rotating driving anvil" must be hardened to RC 58 or harder and have a mirror polish. in which case there will only show a very small burnished spot on the end of the dovetail sight base. Which in itself would be almost unseen.
And if this be too objectionable then the anvil must drive without rotating, which is a simple matter to correct by using a hollow internal threaded thimble driving a keyed, sliding anvil. In which there would still appear a small presure spot which would be difficult to see with the unaided eye.
Incidentally; Hard scrubbing of any soft metal on the sight dovetail or any portion of the weapon will transfer some of the softer material to the point where it contacts and result in some discoloration.
So I would feel uneasy to try anything but a hardened and polished sliding anvil.
PS: one final look at the tool shown appears that the anvil may be a sliding anvil, internally separated from, but driven by, the driving screw
JMO
ViggoG