thanks for all of the suggestions. for those who care:
showed the print to my girlfriend and said "do you think this looks ok" she immediately said" is there something on it down there?" - damnit, that meant a fix was for sure necessary.
dug into an okd MBK cartridge and oh so carefully traced over the spot, then accidentally smudged it, then like an idiot tried to cover up an ink mess with more ink BUT in the end I used my finger to lightly blot/retouch the area, not unlike I used to do when drawing with charcoal. By that point I had a 3.5" long, finger width area that no longer showed the scratch but had an obviously different sheen. I then decided what the heck I'm in it for the education now and who knows so I sprayed it. Of course fate hates me so I got a big black dog hair right on the subject's face in the varnish BUT the one good thing about digging around in wet varnish to remove a hair is that more varnish actually does help. End result, thicker coat than I would have applied otherwise BUT there is no visible change in the sheen where my repair was and in fact no visible anything, so ultimately success!
thanks to all of you!