I ended up making a lens board out of cardboard and taped the lens down to it. Seems to cover 5x7 without vignetting, or at least very little. Works fine on my 4x5. Seems to be equal to a 150-180mm. I pointed it at my desklamp it it ghosted really bad.

BMbikerider: The glass is pristine, I'm surprised it is as good as it is since it was in the bottom of a box full of stuff.