I was watching one of the old interview clips over at Justin's website. In the interviews section there is a lovely clip that can be viewed with real player or quicktime that is quite worth a few minutes of your time, so if you will, clicky here.
If you don't want to watch the whole thing, I believe the bit about Justin and the Olsen Guitar is C or D in the segment clips, but it's only a few minutes, so why not watch the whole thing?
I believe that this is the guitar in question.
Cartoon Saturday
18 hours ago