Assistance please with marking on silver piece.

Silver serving piece is believed to be a cup for serving drawn butter or sauce. It is approx. 5" L x 1 5/16" H. A script engraving of ‘Exeter’ with a crown embossed above is on the bottom. I can find no indication of sliver content or any other identifying markings. We have a set of of eight of these from wife’s mother’s estate. Have searched the web but can’t find any info pointing to the origin of the markings.

Would like to identify maker and any idea of value of the set.

Thank you for any help in identifying.

Photos attached.
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