I agree. That picture is lousy, and the pictures I have of another Mark II (taken at NSL 2013) don't show the ribs very well either.
I can try (if I remember) to get a better-focused picture of the one in the MoF next time I'm up there. I have a much better camera in my phone now than I did that December 2010 day when I took the pictures you have.
John Brohm, who is very detail oriented, wrote an article for a club newsletter detailing how to make the balsa Semroc reproduction nose cone that comes in the Mark II retro-retro kit look much more correct. It contains much detail about number, length and spacing, and is attached. I got it from him in another Mark II thread on here (more just below).
I've done a couple of Mark IIs this way, using 1/32nd basswood as the strips, and it is easy to overdo it. The ribs on the actual sharpener are not that prominent....
Added: Here are some pictures from a Mark II thread on here:
https://www.oldrocketforum.com/show...90&postcount=47
https://www.oldrocketforum.com/show...65&postcount=53
https://www.oldrocketforum.com/show...21&postcount=64
https://www.oldrocketforum.com/show...29&postcount=70
Heck, why not just cruise the entire
thread for yourself. LOTS of pictures of both the actual crayon sharpeners and John Brohm's reproduction idea....