Funny, I just found the SAME buckle on ebay and have two coming in from China at about $2.50 each. I'm going to use them on the sternum strap of my backpacks.

As far as the braiding, its just a cobra sinnet

http://www.animatedknots.com/cobra/

I haven't been a big fan of the cobra due to the work involved in making and (more importantly) dis-assembling it for actual use.
It is possible to hide something long and thin inside the cobra but be aware that this may make the sinnet a bit stiff for a bracelet.

I have been using the chain sinnet for my lanyards

http://www.animatedknots.com/chainsinnet/

which is simpler to untie (a quick pull) but "stores" less cord than the cobra. I use about 8' paracord for my knife lanyard. It works well for me.

To go back to an earlier thread where I asked about a slippery bend so that a lanyard will give safely (in the event that the lanyard unexpectedly hitches on something), I found a good solution:

On one end of my chain sinnet, I make a bight. On the other end, I tie a strangle knot over the bight

http://www.animatedknots.com/strangleend/

With paracord, the bend gives fairly easily but I have to periodically retie the bend because it gives. The strangle knot seems to work better than a constrictor for me.