Ensure the needle still finds North. A "dead" compass can sometimes be re-magnetized, but a cracked jewel bearing is much harder to fix.
Avoid polishing your find! Over-cleaning an antique compass can strip away its historical value and the dark patina that many collectors prize. an original? buy antique compass
The safest route for high-end instruments. They provide provenance and guarantees. Ensure the needle still finds North
Best for "the hunt," but bring a magnifying glass and a magnet (to test if the body is solid brass or just plated steel). buy antique compass
Designed for heavy-duty sighting and map work; these often feature sighting wires and magnification lenses. 2. Verify Authenticity