Regarding the skills used to make such a knot; I would check out this thread - http://forums.army.ca/forums/threads/79610.0
The knots used to make such ropework are not particularly difficult, nor are there a huge number of them to learn. The hard part is getting them to look nice, where to use each one to get the desired effect, and of course having the patience to finish an intricate piece such as a sword knot. There are quite a few online resources for ornamental knotwork such as bell ropes, etc., and they may have info about where to source the gold material to make such ropework. Just make sure you're searching for "ornamental ropework" or "ornamental knotwork".