Hi Hi!
Here are the links to your answers and walk through.
4E
Topical Revision WS Answers (The ones we did on subject day)
https://drive.google.com/folderview?id=0ByCmhBIYPefVNzVJYjVCR1oyb0E&usp=sharing
Prelim Paper Walk-Through
http://choiphysicsclinic.blogspot.co.id/2014/12/henderson-pure-physics-2014-prelim.html
3E
2012 EOY Answer Key
https://drive.google.com/open?id=0ByCmhBIYPefVWHpBenNZbUpnTjA
EOY Revision WS Walk through (Video Quality is not optimal b'cos did it in school)
Please view it AFTER 29 Sep (Youtube is enhancing the video, it will look vertical if it is not enhanced)
https://www.youtube.com/playlist?list=PLjV2zoV7DolVfHBiOd_0I109x_fxSTR7s