I noticed today that there is a fair amount of what looks like dust under the cover for my Vintage gauge speedometer (see attached pic). Has anyone else encountered this problem?

I think the covers can be removed without getting behind the dash or removing the entire gauge from the dash but it has been quite a while since I installed them and it would be helpful for someone to confirm. For example, if the covers do come off, are they a press fit or do I need to “unscrew” them to remove the cover?
Thanks
Glenn

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