The Sperry Navigat X MK1 is repairable at sub-unit level. Most failures are the main control PCB, follow-up amplifier or repeaters. A reconditioned PCB is a half-day swap and a fraction of complete-system cost. Past 40,000 hours, a reconditioned complete master compass is usually better value than chasing multiple spares.
No — Sperry shipped the MK1 in multiple hardware revisions. Confirm the part number on the failed PCB before ordering.
Yes, when IMO Resolution A.424(XI) type-approval is intact and the settling-time test is inside performance standard.