Pommel Ring on British Dragoon Swords 18th c.

[Jim McDougall]

With the dragoon swords that evolved for British cavalry from the basket hilt forms of Scotland in the first part of the 18th century, it seems that the guard shields were welded to a ring, which then mounted UNDER the pommel in many cases.

I have a stirrup hilt 'four slot' sword which has this ring guard type setup (I posted it about two years ago) but did not resolve more on this topic.
What I am wondering is when did this means of securing the guard end? and go to the knuckleguard or guard assembly going into the side of the pommel begin?

It seems by 1759 these type swords were being made by Jeffries in London, with the pommel side mount (apparently number of these were made in 1759 for 21st Light Dragoons, who disbanded in 1763).
These were apparently produced in 1756 as a 'test pattern'? for light dragoon regiments being proposed, and I believe first issued to the 15th Light Dragoons.

As this has the pommel ring fixture, I am wondering if possibly this one might have been of these early prototypes (loosely termed pattern 1756)?

In Belvoir Castle, the swords of the 21st Light Dragoons are displayed in a circular panoply, and are of the form described of the 1759 with the pommel side mount. (thanks to Bryce for the photo).

In 1778, the American swordsmith POTTER made cavalry swords designed after these British light dragoon types, and notably included the pommel ring method.

As always, Bryce, Radboud, Will, Glen, I would really appreciate insights.