The Sebring Pottery Company, also known as American Pottery Works was formed in East Liverpool, Ohio by the Sebring family in 1887. About 1899 it moved to Sebring, Ohio, a town founded by the Sebring family.
It was bought in 1943 by National Unit Distributors and the Sebring name disappeared. The Sebring family owned interests and controlled many different pottery companies so the history of Sebring is somewhat confusing.
It took some research but I did find your pattern, it is an earlier pattern probably designed in the late 19th century to early 20th century. The name isXXXXX: Seb #124.

When deciding to purchase this set, you have to consider that it is not common and would be very hard to find in a full set as you note. Extra pieces will have to be looked for over a period of time by putting in the pattern and your needed pieces with several of the China replacement stores online. So depending on the number of serving pieces , which are most valuable, the number of complete place settings, how well the set fits into your decor and lifestyle, and if all the pieces are intact and not chipped, $1500 is not an unfair price to ask for the set. It is a bit high for market value but would be less than retail (depending again on what the pieces are). If you love the set, and it is in excellent condition, a full complete set of 4-5 piece place setting for 8 or more with a nice accompaniment of serving pieces, I would say it is a fair price. My best, Randi

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