DIY YS640 Yoder 2-Piece Heat Deflector

Hey y'all
I have a YS640, it's working great and all, since I normally take the deflector out to direct grill, and not wanting to spend the $$ on the Aussie Tax'd version of the 2-Piece heat deflector (the one with the access door you just need to pull out)...
I'm wondering if anyone has done a DIY version, or is there something vastly different between the two products that means you can't have one without the other?
Any advice appreciated.
Matt
I have a YS640, it's working great and all, since I normally take the deflector out to direct grill, and not wanting to spend the $$ on the Aussie Tax'd version of the 2-Piece heat deflector (the one with the access door you just need to pull out)...
I'm wondering if anyone has done a DIY version, or is there something vastly different between the two products that means you can't have one without the other?
Any advice appreciated.
Matt