Need some help diagnosing a front end shimmy. Options

[KaptKaos]

My car is a fairly stock '73 1.7. Two years ago, I upgraded to turbo tie rods with bump steer spacers. A few weeks ago, I added a Tarret front sway bar and new rear springs.

Recently, I have noticed a slight shimmy in steering wheel. It varies with speed. It slowly seems to be getting worse. Yesterday, I rotated my tires front to back, to see if it was a wheel balance issue. The shimmy persists.

I have gotten advice that I should replace my bearings in the front. I do not know when they were replaced (if ever), so I am considering that as well.

I am looking for a set of procedures that will help me to isolate the problem(s). Ideally, a step-by-step process of things to check that will either identify or eliminate a component as the source of the problem. I don't want to just start replacing things until I find the problem, but I realize that sometimes, cheap replacements are just smart to do anyway (the aforementions bearings).

Thanks in advance for your help with this.