Okay...
I broke the Vaq down at far as humanly possible (since I deepened the rear sight and widened it, too... I had to get all the filings out of the action.) FOr that I used a set of chainsaw honing files. And went SLOW and EASY and checked many things many times. If you try sight work... I won't be responsible for what happens.
For the billboard and the barrel, I used a wide, flat metal file. Remove the ejector rod housing... and BE CAREFUL OF THE HOLE FOR THE SCREW. Before I took it off, I marked where it sat with a pencil... don't file below that line. Bad medicine.....
Then I filed carefully until the stamping of the billboard was no more than fine scratches. Put the file down. You're done with it. Then I took 220 grit sandpaper and did the rest by hand. It not only takes the the rest of the words off, but it removes the deeper gouges of the file. When the words were all gone, I lightly hit the rest of the barrel with the sandpaper until it matched where it was removed. (For this part I did sand where the ejector rod housing sits... but not much. Just enough to make the whole barrel uniform in appearance. PAy particular attention to the area where the barrel meets the frame and around the front sight. (I left the sides and faces of the sight blade alone. I wasn't trying to adjust POA).
Put the sandpaper away. Now take a medium grit steel wool. Polish the whole barrel with it until the fine scratches left by the sandpaper merge into a dull sheen. WHen you think it's good, switch to a fine steel wool, and polish it all again.
NOw... your beauty will be covered with steel filings, grit from sandpaper, and hair from steel wool... take a deep breath and wash it with hot water. Bore, too. BLow all the water out of all the holes, nooks and crannies. Make sure the hole for the screw in the ejector housing is CLEAN. If not, use a cotton swab and be gentle. (Or a water pick or a bit of water under pressure... or compressed air, etc.) WIpe it down, oil as usual, reassemble.
Good luck.
Long days and pleasant nights,
Will