Liam Lawless has developed a method of one-step enlarging/copying using the reversal process and Arista APH lith film. He described the process in Post-Factory Photography, Issue #2, October 1998, and added some refinements in Issue #3. The secret is a flash exposure after the main exposure, reducing contrast and producing a continuous- tone negative. I don't think copies of this magazine are still available, but the address is here if you want to try:(posted 8608 days ago)http://unblinkingeye.com/Articles/Post/post.html.
The editor might turn loose of an old copy for someone with sufficient interest. Also, Liam Lawless is a regular poster on the Alt-Photo mailing list. Write me directly for more info.