AO-1848, 1983, Pearl S. Buck, Add-on Cachet, First Day Cover, SC 1848, Writer (These covers have a slight mark from a label that has been removed)

Add-on cachet is:

A cachet design added to a cover which was originally uncacheted. An add-on cachet should be identified

by maker and date (mine are stamped on the back with the date) so that it is clear that it is not contemporary with the cover.