So I got a copy of the Barnabas glow in the dark poster after all.
There is a button to ask a question, so I asked if he was planning to print any more and told him I had been looking for one forever. He said he might have another one and he did. While it's not the original size, only 11" x 14", and it doesn't glow in the dark, it's a very good illustration. It looks much better than the small magazine ad and I'm happy to have it. He must have found more because you can now order it again on his website which you can go to by cllicking above in the original post.