I will be renting out my camera scan MPR rail system for anyone interested in testing/using.http://www.peterkrogh.com/rrsproto/
I have stages for both 35mm and 6x6 cm (Hasselblad). Both of these produce black border scans on B&W negatives. The 35mm system also works for mounted slides.
The cost for rental is $50/week for a single format, $75/week for both 35mm and 6x6 stages, plus shipping both ways.
You need to have your own Camera, Macro lens, and light-source and tripod.
Let me know if you are interested - peter at peterkrogh.com