Have gotten several vulcanite stemmed estates from SPC, and the stems were in excellent condition.
I'm sure they were. "Buffer only" oxidation removal results in stem shape degradation directly in proportion to the depth of the oxidation. When a trade-in or estate arrives with only a kiss-O-green (or none at all), no problem. When one arrives that's Old School Army/Marine Corps olive drab (or even worse, that weird whitish-yellow color), not so much. For those, keeping things crisp and straight is impossible using only a buffer. Depending on the skill of the operator, the result falls somewhere between an unnatural "smeared/streamlined" look, and a black Play-Doh sculpture.
Come to think of it, I'm pretty sure that SP.com doesn't accept everything they are sent, thus using selectivity to help keep the standard high for what they sell. Too far gone = too much time required to set right, so back it goes.
The source of my distress is
because SP.com is a respected name with high standards and staffed with a number of true experts, DIY people and many semi-pro restorers assume the techniques shown in those videos are how
all pipes should be handled.