Here is a list of top makes of piano to help you find an age of your piano.
Four pianos are known and dated 1796 on the enamel plaque, with numbers from 291 to 470.Kirckman of 1777, possibly the first appearance of a French stand in England Around 1807, a six legged version was introduced, possibly to accommodate the increasing size of the instrument, and to keep in style. The last style, introduced in the early 1820s (a Clementi has surfaced at auction in Dec.Turned legs replaced square tapered legs, and added embellishments of brass collars, turned and reeded, teardrop shapes, etc. 2011, SN 15123, so ~1821, with 4 original legs), returns to four legs, turned or octaganol in shape, which would continue in Europe until the end of square piano production.Only in their last two years of production do we find L&B pianos occasionally with the date of 1796. A second general style sat the piano on a “French Frame” or apron stand that fully enclosed the bottom edge of the piano, and often allowed a lower shelf for music or similar.This style began in the late 1770s (typically without the lower shelf; a Kirckman has surfaced with what appears to be the original French stand and dating to 1777) and continued until the early teens of the 19th C.The earliest pianos are all petite in appearance, generally shallow in case height, and less than 5 feet long.They are often on trestle stands, which may or may not be original, and the nameboard inlay may use a traditional ogee point outline.This aside, some effort has been made to collect dated instruments and use their serial numbers to produce a trend line for dating instruments. Broadwood is unique in having a well maintained and readable pedigree, thanks in part to the records remaining intact and the company still in existence.Broadwood pianos were dated from 1780 until 1805, and less frequently until about 1809.This gives us a nearly gap free dating of Broadwood squares.18th century serial numbers Serial numbers from 1800 to 1820.