Beautiful Piece! I own the Original Oil Painting of Matt Holliday from the 2005 Donruss Diamond Kings cards as well as Original Art of Troy Tulowitzki and both versions of Eric Young Jr from the Topps National Chicle set.
That said, I have one critique - and not meant to upset - just my own opinion - I would have had Cal sign a Matte to frame the piece, not the art itself.
Many will ask why, so I will answer that now.
My brother is a Graphic Artist and has done 'fine arts' pieces as well. Unless asked, some artists do take offense to having another person - even the person who is portrayed - sign their artwork.
If I have access to contact the artist, I will always ask if they are okay with me having a player sign a piece they did - otherwise, I just get a Matte made for the piece and have the player sign that.
Again, not trying to take away from your item - it's gorgeous (and I am a little envious of your relationship with Cal! I have a book I need signed...
) just stating a point of view that is not always considered when getting original art pieces signed.
All the best -