That's not a bad idea at all; taking separations from a still life the old-fashion way.
I'm discouraged to hear, but curious why you say to avoid C-41 negs. Ultimately I'm hoping to make prints from my archive of personal shots, a lot of which are on C-41.
I did a little research about Tartaro Color and I found a lot about Frank Tartaro and the lab. Sounds like you were a part of the golden age!
It's easy to see how ink-jet printing is completely satisfactory for nearly all modern printing needs. However, when you were rolling your last dye-transfer print, I was probably rolling around on a tricycle in "short pants"! For that reason these archaic methods are fascinating & refreshing to me; the preparation, the knowledge behind it, the research & history, but most importantly the physical aspect of actually making it.
Something I'm curious about and don't have a great grasp on is how to correct color. Let's say we want to warm up the lighting in the print; do we affect this in the dying, the matrix or the separation neg?