Thanks for the help so far.
It took some doing, but I did find another Casey single signed ball from a 2006 Leland's auction. I guess they're fairly rare because of his suicide. The sig on my ball compares fairly favorably to that one, and mine's much clearer and bolder. (Link below to Leland's.) But I'm certainly no autograph expert. It looks like theirs sold for $300. I paid only 20 bucks at the sale for mine, so that would be a decent profit.
Any other thoughts on the ball? Should I send it in to get it authenticated? I used to be a PSA member but let my membership expire. How much does it typically cost to authenticate a ball? Not sure it'd be worth the expense. Does it add or detract that he's also written "Brooklyn Dodgers" on the ball? I would think it would add to it, but I don't know what most single signed ball collectors are looking for.
Thanks. Rob
http://lelands.com/Auction/AuctionDetailed/29636?page=2