The title says cross pein, but the picture shows straight pein.  Starting bid of $15

http://www.ebay.com/itm/Vintage-Cross-Peen-Blacksmith-Hammer-H-M-Toolworks-Louisville-/121480003268?ssPageName=ADME:SS:SS:US:1120

Looks like a 3 lb Cross Pein to me but I don't know much about blacksmith stuff.

http://www.ebay.com/itm/Antique-Blacksmith-3-Lb-Forging-Fancy-Hammer-Anvil-Forge-Tool-Different-Nice-/131351240448?pt=LH_DefaultDomain_0&hash=item1e9524df00

After a few weeks or months, all the pictures on eBay are deleted, so for future reference it helps to copy and save the images and repost them... I'm also often a lazy chap and just copy the links into htmp [img] code - that's fine until the original image is deleted or the hosting website closes/changes - so now I use Save As into My Pictures, then post the image...

Here's the two images from the above eBay links:

Looking at the first hammer, and what appears to be more of an axe type pein (It's not rounded) it appears more like a stone mason's hammer than a smith's tool.....

3 more cross pein hammer heads buy-it-now $20.00.

http://www.ebay.com/itm/3-Vintage-Blacksmith-Cross-Peen-Hammer-Heads-2-to-2-1-2-lbs-Vaughan-C-NW-RR-/390977483591?pt=LH_DefaultDomain_0&hash=item5b0812f347