Trust "Gone West" on this one mate - the oral is entirely based on the the Cap 413 and whilst not entirely different UK RT is not exactly the same as the the US either....
I have to also agree that an hour refresh or practice with your flight instructor would be useful too. The actual exam is quite straightforwrd but for some reason still nerve wracking - practise the emergency procedure cos your pretty much guaranteed you will either have a problem or have to relay a problem.
Good Luck