CLS pre-purchase: How can you tell if panels have been replaced?

[nathanso]

There's a set of CLS I'm considering that the owner says he thinks the panels were replaced but he's not sure (he's the second owner). Is there any way to tell if the panels are the originals or not? Any other CLS issues to be aware of?

 

[DTB300]

From another thread someone post a new link for Serial Numbers and determining date of panels. Here was the link to the PDF file:

http://www.martinloganowners.com/~tdacquis/forum/attachment.php?attachmentid=835

Dan