By 1894 Joseph White is at Chesterfield.
By 1899 J. White & Sons.
1914 White & Sons.
By 1928 they are listed as White’s (Music) Ltd.
1936 White’s Music Ltd.
Your piano appears to be after the first world war, press Datemarks on my website.
Email via my website.
If you find old references or links on this site to pianogen.org, they should refer to pianohistory.info