Bearing #N1, 5c + 1c Foods Semi-Postal (#NB1-3), with FDC special purple cachet on the side. With violet MANILA censor mark (Garrett IA2) and MANILA foreign mail censor (Garrett IE1). BEAUTIFUL COVER. 

eBay $510.00. This is a first day commercial use. One of the best that I've seen in recent years.