The German page doesn't really concern kilts, but rather bagpipes.
I believe that the pictures on this page are the ones referenced by the rootsweb person. The writer never mentions a kilt. His focus is solely on the bagpipes. He wanted to take pictures of the pews in order to be able to measure the dimensions of the bagpipes for when he made his own.
Here are more pictures of the pews. They were carved between 1510 and 1530 by Robert Daye, but some have been destroyed by souviner hunters, according the website:
http://www.sackpfeifen.de/diy/alternun.htm

It seems that once again, any knee length piece of clothing is being assumed to be a kilt. And the assumption is not made in the article