It's a towel, so not sure it is a considered ephemera, but found it when cleaning out my deceased mother's house. She had bought it in the 1970s. I was surprised it still existed.
FYI. Mr. Green (Nigel Harman) is in the Marlow Murder Club (S3E1), that aired Sunday night on Masterpiece.
In Episode 5, River (Stellan Skarsgard), says when he arrived in London at age 14, he survived on peanut butter sandwiches. This would be a normal food for someone to survive on in the United States if you didn't have much money.
Was peanut butter cheap and readily available in Britain in the 1960's or 70's when his character was aged 14?