Here's an interesting cover I picked up initially for its flag sticker on the front. Turning it over I was subsequently taken by all the Christmas seals. The Lincoln Gettysburg Address stamp was issued just over month before. Of course the real festive aspect is that it was postmarked on Christmas Day in Christmas Florida.
Possibly Mr. Frog, I don't know. We've seen Christmas Day cancels here before, so I don't know what the practice was in 1948 of postal workers working on Christmas morning. But this cover certainly has Christmas written all over it!