Russian Banknote

Well, I may as well start things off with this thousand-rouble banknote (issued by the Provisional Government in 1917):

(Click on the above images or any of the ones below to see larger versions.)

I was trying to decipher the meaning of the words with the help of a Russian-English dictionary and a (rather bad) Russian textbook. Considering that I had next to no knowledge of the Russian language or alphabet when I began, and that some of the characters are obsolete, it was not so easy. Still, I managed to get the gist of most of the writing.

Some difficult parts:

Basically, from what I could make out, the above is an equation showing how much a rouble is worth in terms of gold. I don't know the exact translation, though, and would very much like to know how "1/15" and "17,424" factor into the equation.

Then there are these two signatures:

I find it somewhat surprising that the words to the left use characters (i.e the first and seventh characters in the first image) that have not been used in Russia since the eighteenth century. Why would those characters be used in this case? Also, what do the two words to the left mean?

Anyway, the point is that the banknote seems to be a goldmine of interesting details (perhaps you can see the faint swastika in the background in the middle of the green side of the banknote . . . the swastika, mind you, does not indicate that the Provisional Government was a bunch of Nazis; at the time it was simply considered a positive, neutral symbol that had been used for centuries in countries around the world).

Any explanations, references, or help in general would be appreciated.