Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
The reason that I haven't written a massive guide for fiddle is that I am a very new Fiddle player. Therefore I just decided to look at a few builds and do a single change or two in the item build.
Also I have chosen one point in Greed instead of 3/3 in quickness. The reason is that this build is expensive and therefore you need a lot of money.
I might ad more of a guide to it later ;).