I thought the last bit at the end was pretty interesting:
EDWARD: Four years ago, the Colonel came to Rizenpool because he happened to see the letter we sent him, right?
AL: That's what he said... he said he was looking for Dad...
EDWARD: But it was possible that he went to Granny's place --
Armstrong appears at that point and interrupts whatever Ed was going to say. I'm thinking, maybe Roy also came to Granny's house to see Winry?