I buy 99%of my estates from thrift stores and refinished many. I tend to buy the most heavily caked and oxidized pipes and negotiate a cheap price cause they are nasty and I am doing them a favor by purchasing the monstrosity
I start with an salt and alcohol treatment followed by soaking the stem in hot water and oxyclean. The alcohol will remove most finishes but I don't care as I'm sanding them down with micro sanding pads along with the stems.
After the initial soak I scrape the now softened build up off with a set of round nose scissors, but I am buying a pipnet system soon. Following the scraping I will sand with 80/120 grit down to the briar.
Most dents and bite marks can be raised in vulcanite by soaking in nearly boiling water. Follow this by wet sanding with 120/220/1k-12K grit finish with polishing with carnauba wax and soft cotton or a cotton buffing wheel. Any dents that cannot be raised can be filled with crazy Glue mixed with activated charcoal then sanded smooth. One can profile the lip with jewelers files and the draw opened up with a drill bit and pin vice.
On the stummel I do the same but dry sanding saving the dust. Any fills removed and filled with mix of the briar dust and crazy Glue, then sanded flush and smooth. I finish sand 1k/12k grit I finish by wiping with mineral oil several times then a buff with carnauba wax.
Most times with a pipe that doesn't have fills or massive bite marks to be removed I can be done in a few hours while watching TV. It makes the most gnarly looking beast into a silky show piece from the way back machine. I have several pipes from the 30s like look like new and smoke like a dream.
Read up on
Reborn Pipes
I have learned a lot from that one site.