... wouldn't the coin have more detail to it?, since a 1861 coin would only have been (at most) 3 to 4 years in circulation?
These fakes were made to look aged, and the casting adds to the illusion as such. Potential buyers, Civil War buffs, will then assume that the piece was resurrected from some battlefield. Note that the names used by the fakers are those of actual Confederate soldiers.
Since the names are in cursive writing, there's also the appearance of these fakes then being personalized, unique pieces. In truth, multiple examples exist for each name. I did spot one, more deceptive example that sold on eBay some months ago. One of these fake dies was apparently applied to a genuine, 1861-O half dollar.
To my knowledge, no Confederate ID disks have as yet been found. There are many hundreds of Union ID disks known; almost exclusively on die struck, Union medals of different patriotic designs. The reverses of these typically half dollar-sized medals were left blank in order accommodate each soldier's personal info - name, rank, regiment, etc.
BTW, I wrote to the seller, telling him how to easily verify this fake. He did not reply. I've reported it to eBay. I'm expecting that some buyer will likely get stung on this purchase; this, given the rising bids and as the seller offers no returns.
An easy to spot fake
For some, yes. Over the years, I've encountered a number of otherwise knowledgeable coin dealers who've been fooled by these. IMHO, Civil War buffs are generally more susceptible to being victimized by these "fantasy" fakes.