This article is from the Misc Bicycles FAQs, by various authors.
Cleaning up the braze-ons was a pretty simple process again. Using
sandpaper as much as possible and then small files to get into hard to
reach areas. The harder ones to do were the pump peg and seat peg
because of their design. Ron had done a good job of not leaving much
silver around so it went quickly at each braze-on, but there were a
dozen of so of them.
This final cleanup also included filing off the brass left at the vent
holes and sanding this off again.