Tim, what I have tried to show here is not that I dug up another sword with a similar guard-- that tends to leads to "the chicken or the egg" reasoning. Rather, I am trying to present the notion that one ought to search out and recognise formal groups, in this case guards, which tie together like examples.
Here is another of this type:
http://cgi.ebay.com/OLD-CONTINENTAL-...QQcmdZViewItem
Comparison leads to second deduction-- these similarly-hilted weapons share a spectrum of blade forms: we have one mounted as a yataghan, one symmetrical and another single-edged. This also supports a European origin for the sword under examination. The most general requirement I suppose is to broaden one's knowledge of forms as much as possible. Fortunately for most of us, it's a pleasure.
As for the scratches on the guard, I can barely make them out I'm afraid. However given the condition of the ferrule relative to the guard, I would suggest that the scratches are indicative of cleaning which was more enthusiastic than skilled. Finally, I don't seem to be able to find any Chinese swords in any of my references with guards that bear more than a vague similarity with that of the one under discussion. Can you provide an example please?
Ham