Hi Virginia,

Thank you for contacting Mearto with your appraisal inquiry.
The iron-red mark is too eroded to know who made this plate but as you rightly point out, the uneveness of the plate, the quality of the glaze and bright enamel colors denote its age. Though this has true age, it's neither very rare or valuable - literally hundreds if not thousands are on the market at any given time - and considered more decorative than historically important.
Based on the photos and information provided, and subject to examination, this is:

An antique Chinese export famille verte enamel decorated plate
19th Century
Decorated with stylized foliage, interlocking red chains and other auspicious symbols, the verso bearing remains of an iron-red character mark and a paper label for Lina's Interiors, a Greenville, Mass., antiques store.
5-1/4 inches diameter
CONDITION: This plate appears to be in good condition with some minor pitting to glaze commensurate to age and use.
PROVENANCE: Acquired from a gallery or dealer
$125-175*
*represents a fair-market value for auction purposes; retail or asking price may vary.

Please let us know if you have additional items to appraise, or questions/concerns, and thank you again for using Mearto.
~ Delia