Okay - so we can rule out eggshell porcelain.
The piece is creamware or some similar earthenware. It appears to be in great condition, too. The only detriment I see are the repair and the inability to identify the maker.
It is apparently English, and dates to circa 1830 - 1850.
If your pot and cover are in perfect condition, the current retail (replacement or insurance) value of this item is approximately GBP300. If you were to sell it, you could expect to get the fair market (private sale or auction) value of approximately 40$ of the retail amount, or GBP120, depending on location and actual condition.
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