I have duplicated a lot of 35mm transparencies in the past on Kodak 5071. I used a Contax SLR with a bellows and slide copy attachment, plus the Zeiss 60mm Makro Planar lens. My light source was a enlarger color head. I bought 100 foot rolls of film and bulk loaded (each lot of 5071 needed to be tested in my setup).
Currently, I just scan the slides (and/or negatives) to a CD. Then I send the CD to a lab for printing to slide film.