It's not pre war, but this is definitely my holy grail:
In 1967 my father, 16 at the time, peeled a bunch of Topps test issue Red Sox stickers and stuck them to the door between his parents' garage and dining room. I spent a lot of time at my grandparents' house in the 80's and the stickers were still there. I remember Reggie smith, petrocelli, Lonborg, a few others, but the one that stood out was Yaz.
Years later, I became a serious Yaz collector. Given the nostalgia factor and the scarcity, an intact copy of that sticker became my holy grail. I had a meager budget at the time and knew there was no way I could afford one.
Then in 2014 I was contacted on CU by a rabid Carlton Fisk collector. He had seen a rare Fisk proof I had posted and offered to buy it. I had been watching the sticker above on eBay, wishing I could afford it. I told the Fisk guy that if he could get the Yaz sticker, we could trade. He accepted and a (long) week later the sticker was in my hands.
It's a scarce issue of my favorite player, in a much nicer grade than I dreamed about, but more than that it's a reclaimed part of my father's childhood and a reminder of happy times with my grandparents. I would never part with this card.