I noticed that a link to Mr. Kelly's essay on blade geometry had been added to my original post, which I had read some time ago, but a re-read made me notice the "opposed fullers" illustration - fullers cut offset into opposite sides of the blade. I don't believe I've ever seen this on a historical example; granted, I usually only get to see whichever side is up in the museum display, but I've never noticed a fuller or grouping that was off-center. What time period is that fuller arrangement common to? It seems like a tricky way to cut fullers into a blade without sacrificing the thickest part, if someone were trying to tune up a blade that can't afford to loose any spine thickness.

I don't suppose anyone has seen something like that on a type XVIII or XVa...?

Thanks again!
Eric

Opposing fullers are mostly found on very late-period swords dating 18-19th century. You won't find it on an Oakeshott Type XVIII or Type XVa because, then, it wouldn't be of that type any longer.

http://www.oriental-arms.co.il/item.php?id=2746
I've only seen them one double-edged blades from the Caucasus area, the kindjal and qama are two types that often have them. I'm not sure how far back these designs go, but I've always had a fondness for them.
http://www.oriental-arms.co.il/item.php?id=2726