Minor scratches on gold watch cases can be removed with a clean, soft cloth and a little metal cleaner. Watchmakers usually use a Dremel machine buffer, but it’s not necessary for minor, do-it-yourself jobs.
The basic essentials for buffing a gold watch are some old clean rags, Brasso Brass cleaner, dish soap and a toothbrush, according to Thewatcchguy.homestead.com.
It’s not required to remove the mechanical movement from its case to buff out scratches, but older watches are easy to disassemble by prying open the snap-on case back with a fingernail and removing the movement. The crystal and bezel will unscrew from the case.
Gently use the toothbrush and dish soap to thoroughly clean the case and case back. Dry thoroughly with a clean cloth.
Rub in the Brasso with a clean cloth. It works on stainless steel, gold and gold-filled cases, but remember that it will remove a micro-thin layer of gold plating. Be conservative when buffing. The gold finish can easily be ruined.
Wipe the case and case back down and put the watch together. If you are not disassembling the watch, be careful not to put Brasso on the crystal.