The 5-pointed Star in the oval denotes a fineness of 91.5 percent minimum fineness hallmark, and this hallmark is from Spain. The 5-pointed Star is made with lines, but when worn down the star appears solid, and you can see this beginning to occur with your hallmark. Not sure about the Centaur ...
Have a tea set that I am trying to do research on and all the oieces feature a star and a centaur. We have alot of Danmark stamped items so I figure its from the same region.