I was finally able to install the new battery tray I received from RC-Monster 2 months ago while I was on deployment. I also installed a plastic screen on top of the fan to prevent any peebles from getting into it. The original POS Castle fan is broke so I replaced it with an Evercool 30mm x 30mm x 7mm computer fan. I just need to remove the plug from the Castle fan and solder it into this new fan. I also installed the body I bought from Respi a few months back.
Anyway, here are some pics.
Broken POS Castle fans:
Evercool comp fan with Castle fan plug:
Plastic mesh to serve as screen:
New battery tray:
New body: