The stones mentioned (ruby, ceramic, Arkansas) are simply varieties of hard stones used for polishing and smoothing metal parts. The "jeweling" is what I and others described, used to retain lubricant. In other words, he is really just polishing parts like every other gunsmith that does action work or "trigger jobs" as they are sometimes called.
Never having seen any of Mr. Jacobson's work, I cannot comment on how good it is, but too much in the way of such work can result in guns that have a small problem - they don't fire. I have seen several, one of which cost the owner almost $2000 in gunsmith charges. Fortunately, it was his pin gun, not a defense gun, but the bowling pins did not fall down when he clicked at them.
Jim
Never having seen any of Mr. Jacobson's work, I cannot comment on how good it is, but too much in the way of such work can result in guns that have a small problem - they don't fire. I have seen several, one of which cost the owner almost $2000 in gunsmith charges. Fortunately, it was his pin gun, not a defense gun, but the bowling pins did not fall down when he clicked at them.
Jim