[canjond]

All in all, Cobb bank checks are pretty good and relatively inexpensive so an authentic Cobb signature. I can't recall off the top of my head, but there are a few years to watch out for (I think Cobb's wife may have signed a few checks). Generally I'd probably stick to an authenticated Cobb check, simply for piece of mind even though very few may be forgeries.

I'm not sure if green vs. blue/black has much of a value difference. Personally I like the green as that is what Cobb preferred to use. One thing to look our for, however, is making sure you get a clean signature. There are so many Cobb checks out there, wait until you find one with no cancellation marks or stamps around or through the signature. I also tend to like checks without folds and that are very bold.