It has always been 'clear' in my mind that Tower's Great-great-grandfather had the letter directly from Steven's father. But was there any direct hint of that in the Books? (I thought there was).
Ah well, I'll have to read them again & see *bother*
Brainslinger, what's this..
Spoiler:
... is this more comic 'new-cannon'? Dunno if I'm fond of such.