Thanks CharlesE but he oil seems to rise from the lower to the higher on the face.

Actually CharlesE, the "sheen" seems to be creeping from bottom up! I took a photo of it with my phone but don't know how to get onto this site! Me and the 21st Century are having difficulties communicating, to say the least!

Do you need a replacement gauge cluster?

I had wanted to keep this original unit because it shows the true mileage on the chassis. If / When I grow a pair, I may attempt to remove it and find out what can be done to alleviate this "cosmetic for now" issue.