Radboud, these notes and observations are outstanding and I thank you so much for detailing them out so well, and well illustrated . While I have good familiarity with British military swords you and Bryce have truly focused on these kinds of peculiarities well...........busily adjusting notes!
It is these kinds of posts that become so valuable in our archives here, and essential in future research as more examples come into these pages.
It truly is interesting to see, as you well note, the 'conventions' really were not consistant before 1788 and the later regulation patterns and protocols.
Toaster, excellent example in perfect accord with the OP, earlier form hilt on later Gill blade, thank you.
Peter, great and unusual example of the five ball hilt. These are typically termed spadroons for the straight SE blades they were mounted with, so this saber blade is an anomaly. ....excellent perspective!