Tooling

Poconopete,

On the Bust Half you posted in the grading section, a favorite for tooling is the clasp on the drape over Liberty's shoulder. It is a higher point on the design and shows wear when circulated. Coin doctors will use engraving tools to carve a new oval in the clasp so it appears "less worn". Most times if the work is expertly done you can only see evidence through high magnification. The hair, another design high point, is also tooled.

The experts, including corrupt engravers, use standard engraving tools (chisels, vise, rotating easel, and magnifiers) to do their dirty work.

Especially under magnification, you will see lines where an individual "tooled" with a very fine pointed instrument around the devices. It's a doctored coin at this point, and the buyer should use extreme caution as this coin (especially the keys) will be dramatically reduced in value as well as unsubmittable to any TPG.