OK. Found a stew pot at the local thrift store ($4).
It has a surface area 5.81 TIMES larger than the pop bottle. That should make a difference !!
I also found a 8.5x11 glass sheet at the Dollar store for ($1.50). It was in a Certificate frame.
That will hold the Peachy perfectly without having to hack together some weird mounting bracket.

Now for calibration and print tests (on glow paper)