To find a compatible starter, you'd need to:
* Identify the starter's part number: This is the most reliable way. The number should be stamped on the starter itself.
* Use a parts catalog: Use the year, make, model, and engine size (likely a big block Ford V8) to find a compatible starter in a parts catalog like those from NAPA, AutoZone, or Advance Auto Parts. These catalogs cross-reference part numbers.
* Check online auto parts retailers: Websites like RockAuto allow searches by year, make, and model, often listing multiple starter options with compatibility notes.
Searching for "1968 Lincoln Mark III starter motor" on these sites is the best approach. You'll likely find several compatible starters, but they won't necessarily be identical to the original.