Ok, no more discussion about the "D" word. The only reason I mentioned it was to avoid having folks respond by telling me to go out and shoot wet plate or real tintypes. Unfortunately, I can't do that for this project.
What you are trying to accomplish could use any type of negative, and there are good reasons why someone could want to do it with a "real" one in an enlarger. Going out with a regular film camera and making "tintypes" from the camera negatives/copy positives in the darkroom is an interesting idea. I am embarking on making 20x24 negatives from 4x5 for "cyanowhite" contact printing by making a 4x5 contact positive and then enlarging it onto 20x24 APHS.