Their website, which is still online, speaks for that. However, it seems they were a bit too dependent on checking with their user base and didn't get very far. Their only output that wasn't online were two unabridged recordings of The Wonderful Wizard of Oz and The Emerald City of Oz on audio cassette.
Now, these were not a straightforward reading of the books by a narrator. They had a cast providing voices for the characters, just like a certain podcast does when they present a story...
Overall, this is a suitable unabridged recording. There is no music or other added sound effects, however, I thought the voice for the Nome King was too deep and gruff, and Billina and Glinda (and possibly other characters) had an echo in their voice. All together, as admirable as this is, I can't really think of a reason to recommend it over a free Librivox audio book. While it's a good audio book, the multi-voice cast is still obviously just reading their dialogue.
If you want a copy, this is one case where I've had trouble locating copies for sale, except Amazon, where the prices are well over the original price of $20, and frankly, that would be the maximum asking price for it. If you must add it to your collection, keep an eye on eBay or even Paperbackswap.com. Or perhaps someone who isn't thinking "rare equals valuable!" will put one on Amazon at a reasonable price.