My DH is an engineer and leaves me little diagrams of stuff. Yikes! Does he think I am stupid or just has a compulsion to diagram everything? Must be a compulsion? He even has a certain way he tears off the grocery list. What do they do to these people in engineering school? My son says that stuff drives him crazy. After 27 years, I just ignore it. He does come in handy at times.
Enjoy your bator. What a find! That letter will be priceless to you someday. There are many things money can't buy.