1936 Great Britain mourning cover for King George V from Windsor to Preston postmarked 28 January 1936
stamp by <a href="https://en.wikipedia.org/wiki/General_Post_Office" class="extiw" title="w:General Post Office">w:General Post Office</a>
<a rel="nofollow" class="external text" href="https://www.shapell.org/historical-perspectives/curated-manuscripts/mourning-stationery/">Direct image source</a> linked from <a rel="nofollow" class="external text" href="https://www.andrewglajer.co.uk/shop/george-v/photogravure/covers-pg/sg439-1936-mourning-cover-windsor-to-preston-with-1-2d-photogravure-html/">this webpage</a>