Thanks Nik and Phil. I've since added a SHO version to my Astrobin gallery. I did a version (not put up anywhere) that tried to go sharper but up close it looked too much like pencil drawing to me. Maybe that's not a bad thing from a distance? Anyway, I might yet get more detail with a reprocess.
Astrobin:
https://www.astrobin.com/full/s81kbk/0/?nc=user