Hello Estelyn -
Found one more. The centerfold poster of the 1977 Tolkien calendar by the Bros Hildebrandt is all of the dwarves, Bilbo, and Gandalf and is titled "An Unexpected Party." You can see it on the Spiderweb Art site:
http://www.spiderwebart.com/productsd.asp?snob=104794
I didn't try this, but it looks like you could download this illustration here:
http://galeria.tolkienianos.com/deta...?image_id=1083
Without a lot of effort (essentially using Google), you could probably several other sources of this particular illustration.
Hope this helps.
Away from The Green Hill Country,
Parmastahir