Possible Clues:

• Old soldier pierced by end of bayonet is still alive
• Old lover with blemish, not one still with us
• Extension covers colour still in existence
• Though top's gone missing navigational aid is still going strong
• Still in existence once Nat returns on time
• Top navigator's aid still around
• Still being taken out of context, antagonistically
• Surviving antique navigation instrument has lost its top
• Navigational instrument fails to display miles ultimately remaining
• The top is missing from a navigational aid still in use