I buy a lot of estate pipes.Most of them I get,the stems are oxidized(green,brown,yellow).The ones that are really bad I give them a bath in Oxyclean(I have also used bleach.If this step is needed,I use a Qtip and a little vaseline,and dab the Logo mark,if there is one,one the stem.This keeps the oxidizing agents from taking away its luster.The teeth mark removal,I start with 320 grit sandpaper,then 400,onto 600.I find it best to wet sand all three grades.I then move on to my buffer.I use brown tripoli to start with.It is more abbrasive polish,it will remove away the scratches from the sandpaper.Be careful,stay away from the tenons,and the ends of the stems(could end up with loose fit)After the tripoli,I use white diamond tripoli,It brings the shine through,like a mirror!After the polishing,I use pure carnuba wax,to put the final shine to the stem.All the polishes should be done with a different wheel,as not to mix the abbrasives.The best speed to run the buffer at is 1725-1750 rpms.Any more just melts the wax.I use the carnuba on bowls too,it puts a mirror shine to them as well.I hope this was helpful