Remember that from 1900 on (hell, even in the 1800s) most cameras could take very nice sharp images. So you'll have to find a crappy one if you want a degraded "vintage" look.
The box camera might just be the ticket. No focus, crummy lens, but they should still be sharp enough to be more than usable.
Something like this:
Otherwise maybe pick up a 4x5 speed graphic. You can mount any lens on it, including things like magnifying glasses from the dollar store, old projector lenses, etc, which will give you plenty of interesting aberrations to play with. The speed graphic has a focal plane shutter (unlike most other large format cameras) so you can shoot through any piece of glass (or plastic!) imaginable - you don't need it to be mounted in its own shutter.
Finally you might try screwing with negative desecration... like gandolfi's "kill your darlings":