Mark, a quill pen cannot turn a corner that small, especially on vellum, which is textured. It can make a hook, but not a triangle at that scale. I've used quill pens. I know this from first-hand experience.
Higher resolution scans won't tell you anything more than what you can see from existing scans because the writing implement is not capable of microscopic details.
Look at the example I posted in #86. Look at the t in the otol front of the scribble. Look how the line wiggles and shakes on the textured substrate. You can get a finer line by turning the nib sideways, but there's a limit and that little collection of lines is hitting the limits of what is physically possible.
Higher resolution scans won't tell you anything more than what you can see from existing scans because the writing implement is not capable of microscopic details.
Look at the example I posted in #86. Look at the t in the otol front of the scribble. Look how the line wiggles and shakes on the textured substrate. You can get a finer line by turning the nib sideways, but there's a limit and that little collection of lines is hitting the limits of what is physically possible.