Got excited when I found this thread, but none of the files show up for me (not a member), but it also looks like the file guy edited his posts recently and maybe deleted them? http://www.rcgroups.com/forums/showthread.php?t=1696095
Update, got this to work, I don't know about the replication as it was just made by someone who wanted to do this.
It appears that the file above in the picture is actually for the arms of a Q-450 knock off DJI. I have those arms here and they are exactly the same as the screen shot. But different from an official DJI arm.
I saw a video on YouTube somewhere where a guy shows the arms being more flexible than the stock DJI arms. He ended up changing them because he felt they contributed to vibration being transmitted back to the flight controller.