Mirror is a role claimed by a source; verification requires independent evidence about the particular address and the time it was assessed.
Treat the label as a claim
Capture where the Mars Market mirror label was seen and who applied it.
A label can be copied to an unrelated destination, so it is a starting point rather than a result.
Separate continuity from availability
A mirror may respond to requests while still lacking evidence that it continues an earlier service.
Document response behavior and provenance as separate findings.
Keep destination handling non-operational
Use descriptive records instead of publishing unverified navigation targets.
This keeps review material informative while avoiding an unsupported routing decision.