Frank, thanks for showing us this image and the detail that you have extracted from it.
How many images have you combined here and what exposure separation between them did you choose?
this is only one picture shot in RAW. I guess the DR of the D850 is higher than the DR of the film. That means that I can extract details from the shadows and the highlights by
a. converting the NEF without losing shadows or highlights
b. Developing the 16 Bit Tiff result with a HDR plugin in Photoshop.
Example: The red jacket is black in the slide projection, but the D850 can see it as underexposed color...