I saw the other thread. Certainly looks like the same design. If you are "crafty", you could even one for yourself -- which I think I'll probably try.
Based on his instructions, I would think it would be fairly easy to modify it to accommodate the Sony PRS-505. Basically, if you have the original cover that the reader came with, cut off the plastic strip/bracket. Then, glue the plastic strip/bracket to the inside cover of the leather book before the step where you are gluing in the marble paper lining. This would allow the reader to move freely back and forth in the cover just as it does with the stock covers. That would give you access to the top and bottom edge of the reader for syncing, turning on the power and inserting memory cards etc.
For relative newbies like myself and anyone that doesn't feel like "archive diving", here's the information from the earlier threads:
A review by a fellow mobilread member:
http://www.trendoriginal.com/2008/06...dle-book-case/
Detailed instructions on how to make your own:
http://imageevent.com/artsci/kindle
The earlier thread where this cover was originally discussed:
https://www.mobileread.com/forums/sho...her+Book+Cover
Cheers...