Well, I have to say, I'm now surely hooked. I certainly did not expect to find a character such as that of "Dick Swiveler" (what a name!). in this book (at least not this early). He's certainly there for great comic relief, from the description of him. I do like that I've got a new euphemism for being drunk:
"the sun is very strong in my eyes"
..it was also nice to note that Dick was given the chance to espouse what the relationship between the old man and Fred really is like, since this gives his character a little more weight. He may be frivolous externally, but he notices things as well.
It certainly leaves us wondering which version of the truth is right. Since we (and the narrator) have known the grandfather longer, we'd be inclined to believe him...but, I wonder if we should.