I to was trying to find out the location of the sword, I got in contact with a curator at the tower of London and this is the reply to my email inquiring to whether or not the sword was still in the collections of the tower. It does not give a definite answer, but if true it would answer some questions at least.
The Small Armoury at the Tower displayed material from both 1715 and 1745 Jacobite uprisings, and there was indeed a sword described as An Highlanders Broadsword. According to the earliest published Guide (Boremans childrens guide of 1741) there was a large broadsword with which a Highlander struck General Evans, and cut him through his hat, wig and scull cap; as a result Evans either shot the highlander with his pistol or pardoned him as a worthy adversary which is not made clear. John Hamiltons illustration of the weapons displayed in the Tower purportedly used against the English and published in 1795 shows a basket hilted broadsword, but the detail is not sufficient to identify the original sword.
The story of Evans misadventure is continued in Guides until the 1780s. In 1784 it is noted that the display is under reparation. Thereafter Highlanders arms are mentioned, but individual descriptions are reserved for the Earl of Mars elegant shield and Exquisite piece with mother of pearl inlay ( a firearm), highlanders curious all steel carbines taken in 1715, the Scottish swords of Justice and Mercy carried before the old Pretender on his being proclaimed King of Scotland in 1715 and the lochaber axe supposedly used to kill Col Gardiner at the Battle of Preston Pans (September 1745). The latter swords remain in the Collection they are currently displayed on the first floor of the White Tower but while we have a number of basket hilted swords, some of which are Scottish, Im afraid the great highlander sword has vanished and cannot now be identified. It is possible that it was destroyed in the Great Fire of 1841 which swept through the Grand Storehouse and its displays, among which was the Small Armoury.
Reply posted by : Shane Lanphear