Hey there! I didn't do revs but after checking out past exams it doesn't seem
too different to ancient history in terms of structure.
It's perfectly ok to be spending hours on a set of source analysis at the moment as you've still got months till your exam. Just keep practicing often under timed conditions and you'll find that the time will cut down after a while. In the final exam, the recommended time for a 20-mark source analysis is
30 minutes (5 minutes on a), 10 minutes on b), 15 on c)), however it's recommended to use no more than 27 minutes in order to give yourself time to check over your responses at the end.
As for tips on writing faster, the best way is to just keep practicing. No one is able to write a perfect SA in 30 minutes at the start of the year, however if you keep practicing, it will become a lot easier and more natural. Also if you do enough practice, chances are you'll end up writing on a topic you've already written on in a SAC/exam, so you won't have to spend time thinking of new ideas.
Another tip is to really know what the question is asking for. In ancient history (this probably also apply to revs), many students spend too much time providing information that's
not relevant to the question. If you can quickly identify what the question wants, and write an efficient answer that clearly addresses the topic and doesn't go off tangents, you'll also cut down your time significantly.
You might want to check everything I wrote above with someone who actually does/did revs
Good luck!