@lewm And that is why Howard Johnson's made 28 flavors. Best Hot Dogs ever.
The idea behind a suspension Lew is to isolate the cartridge from all environmental mechanical vibration including anything coming from it's own plinth including the dust cover. I can turn the volume all the way up and tap all over that dust cover and you can not hear a peep. If I give it too hard a lateral blow the table will skip because I provided an impulse below the suspension's cut off frequency. Anything above will be filtered out. Now in your case, you have a slate plinth and no hinges. We are both old men, but as you previously related you are 10 years older which makes you REALLY old. Any really old man trying to put an unhinged dustcover on a running turntable is a recipe for disaster. It is not such a great idea for just a plain old man never mind a young man with an essential tremor.
@rauliruegas Pardon for the late reply. I stumbled over an old post of yours. Forgot to push the "LAST" button.