Plato wrote:Williams Sonoma "claims" that their data base does not extend back that far. Their current Web Site offers only recent recipes.
Well, I can honestly say that I have lost lots of things since the 70s. So, it is entirely possible. Maybe consider writing Chuck Williams himself. Back in the day, he ran the company and its marketing efforts day to day. Perhaps he has in in his personal recipes. I understand that, at 93, he still works frequently at the company's headquarters in San Francisco.
On another I would love to fiond a recipe for a chocolate trifle that was in a Bon Appetit issue in the early 90s. Unfortunately, the Epicurious database doesn't extend back that far.