You can purchase these types of flat lens housing from Eye of Mine and other 3rd party suppliers, and will run you about $70 the last time I checked. I had an extra housing, so I decided to go with the DIY model. Using trusty ol' Google, I stumbled across this site which basically was exactly what I was looking for. The guys at Jazz and Fly fishing deserve all of the credit, and I just replicated what they did with a few minor tweaks. I ordered a 58mm UV lens off Amazon for a few dollars, and a couple of Avent Baby bottles. I had the Epoxy already, and I used spray paint versus magic marker to get the cap black.
I used a dremel tool to adjust the avent bottle cap to the right inner and out diameter, versus using a hobby knife. I used an old lens cap off an old camcorder to protect the new lens, and secured it in place for travel with rubber bands.
So, does it work?
I was dying to test it out, so I filled a large stainless steel pot, and recorded a couple quick movies using the original housing, and the new flat lens housing. The original housing is blurry, and you cannot read the card that I was holding on the bottom. The new flat lens housing was a drastic improvement. The words are instantly readable. I'll post some video of something more interesting now that I know that it works! See for yourself: