It looks like he might of had it wrapped in a Frog matt at some point, possibly until it firmed up.

The one I am cutting vertically I did in 2007 and I did not.  The 2nd one had to be mats as that is the only way that pattern would have shown up!  Not sure why I used them the 2nd time!

Sir,
You just made my day. I love Gyros and will definitely be trying this!