I'm so glad you like the site!!
I will be adding some new things very soon.
There will be a page up with sound clips of Harpo's appearances on various radio shows.
And I am going to put more clips of the Ed Sullivan show up too. There is one scene where they ask Harpo what he is going to play and he actually says (though quite low, but still audible) "the harp". He then plays the harmonica. Then there is a scene where you can hear him laugh. That is quite low also, but still audible. He sounds just like Chico when he laughs.
There is an episode of the Milton Berle show that I saw at the Museum of Broadcating in New York and he laughs on that and that is very audible. I wish I had that episode!!!! If I do ever find it, I will put it up here.