Home built fan aspirated radiation shield

I’ve been thinking about this, and wondering whether there isn’t an easier way of doing this without all the cutting, filling and painting, and I’ve come up with this:

http://www.headcook.co.uk/kaiser-tinplate-loose-base-quiche-15cm-p-331.html

My first question would be whether anyone knows whether there would be a disadvantage of using silver metal as opposed to white plastic? Otherwise, you could use these for the layers of the pagoda with no need to cut the centres out, and no need to fill the lips.

Whadya think?