S Stamp on British Swords

[Bryce]

G'day Jim,
Henry Osborn was using the G and also GG long before he partnered with John Gunby. Recently I have become aware that earlier (possibly 1780's) Henry Osborn had been marking his swords with a Crown over HO stamp. I have an early (probably circa 1796) 1796 light cavalry sabre marked to Osborn, which I believed had a corroded G stamp on the ricasso. Now I think the mark may actually be a crown with the HO hidden beneath the guard? I have seen on the internet another 1796 sabre with what looks to be a crown over HO stamp.

Henry Yallop from the Royal Armouries confirmed that a sword like the one shown below from Jonathan Barrett's website, with the crown over HO stamp, was also stamped H.OSBORN on the tang.

Why Osborn used a G stamp is still a mystery, but I have never seen a Gill marked sword with a G stamp.
Cheers,
Bryce