That front spring shackle concerns me. It may not be the cause of the shimmy but it needs to be addressed. If that is a import they are prone to breakage and by the looks of yours it could be. http://www.fordgarage.com/pages/brokenshackles.htm
Replace them with the USA made ones from Snyder's. They don't look originl but I would rather be safe. https://www.snydersantiqueauto.com/P...earchByKeyword
Here is a picture of one of mine off the rear that I recently replaced.
