I agree with Josh, seeing it as a Republican era piece. Examples like these with the highly polished blades/potential plated blades can sometimes be seen with characters etched on them as well. Their numbers, material composition and style suggest to me some measure of mass production. Of course that is a relative statement in the realm of Chinese swords. That being said, I think they are rather recent.
As always, dating Chinese swords is an imperfect science. I did see a sword of this type in some old World War Two related footage. Clearly more evidence with time points associated with them would give us a better view of the age of these weapons.
Here is a link with an interesting photo that suggests a possible date for the picture shown. There is a lot of good photos on the rest of the site too.
http://www.virtualshanghai.net/Image.php?ID=19458