How high is the resolution?

The nature of film is that it will record about 2500 x 4000 pixels.

Try this experiment: Take a single good film frame with somewhat extreme exposure range, but one that you wouldn't have to dodge or burn to get an acceptable print.

1. Produce a print from the negative.

2. Scan the negative at successive resolutions, starting at a level well below the known resolution of film, and continuing up to, say 4000 x 6000 pixels. It is critical that the neg not move between scans.

3. From each scan make a print, blowing up a crop of the image.

4. Examine them: Can you see a difference.

Take the scans. Expand and interpolate each to the size of the largest scan. Now use photoshop, or netpbm and subtract one image from the other, and then renormalize the contrast. You may have to do this both ways A-B and B-A.

This will give you a measure of the detail difference between images.

My expectation is that if the high res scan is over 2500 x 4000 x 12 bit depth that the differences between images are going to look like sandpaper. If there were real differences there would be some degree of ghost image.

Now: from your scans, can you print an image that is comparable to the one printed from the negative. This will require calibrating a printer, and really needs a photograde printer to do so, OR access to an online system for printing.

If you can pass these tests, then the high resolution scan should be sufficient. Proceed from there.