My little contribution to the 16mm film community. I have created a 3D printable model of an adapter that will let you use a cheap Bell and Howell super 8mm lens (28mm) on a 16mm ELMO projector lens barrel (40mm). I you have access to a 3D printer you can download the 3D file and print the part for free or go to a 3D printing service and the part printed for you. You can also order the part for my store at Shapeways.com from $20.46 USD. With this adapter using the B&H 1inch f/1.6 lens you easily get twice the image size of the default 50mm ELMO lens. Both B&H lens and adapter are far cheaper than an ELMO wide angle lens.
I got mine printed for free at the University where I am a professor. Expect to do some sanding to get a good fit.
Download the part or order it here:
http://www.shapeways.com/shops/julian_baquero