The sideways EP mean Electro Plated, the EPNS means Electro Plated Nickel Silver, and B& GGS is the Sheffield, England maker Boardman and Glossop, the number being the pattern number. All of thee pieces ate late 1800's, early 1900's English silver plate (not sterling) and have values of
$100 for the coffee set, $10 each for spoons, $10 for sugar tongs, and $20 for salt and pepper shakers.
Some sites that I recommend for selling are Varagesale.com, Ioffer.com, OfferUp.com, Ebay and letgo.com.
You can also go to invaluable.com or liveauctioneers.com and search their directory for an auction house near you and consign to them.
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