Carpathian elm is grown in the Carpathian mountains in Europe. The reason you only find CEB as veneers on eBay is that it's illegal to import CEB into the US in any form other than as veneers, due to a quarantine in effect as a result of Dutch elm disease. Pen blanks from existing old stock are perfectly legal to own, but none can be imported, except as veneers. This is why CEB pen blanks are virtually impossible to find on eBay.
What distinguishes CEB from other elm burls is primarily just origin and pedigree and not necessarily appearance. Prime CEB is very pretty but so can be other prime elm burls. If similar appearance will satisfy your need and curiosity, my advice is just to get regular elm burls, unless you're hung up on the notion of getting your hands on forbidden fruits.
Steve
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