Jim the blade does have traces of gold writing on it, pictured below. The second picture was surely a maker's signature, only a faint piece remains sadly.
Osman is 100% sure it is Ottoman, I trust him on that point he is an expert on Ottoman blades.
As for the velvet, every single mameluke with this style of fittings I can find has velvet on the scabbard.
See Dellar PG 112 fig 12.9/12.10
More examples of similar swords:
https://www.michaeldlong.com/product...l-dress-sword/
https://www.pinterest.com/pin/487936940879693718/
There are many 9th lancer's that look almost the same, hard to differentiate if its the same sword being sold over and over again.
https://bid.antonycribb.com/m/lot-de...F29%3Fpage%3D9
Take note of the fittings on the previous swords and my sword, they're very similar. It's impossible to prove that it is for sure a Lancer's sword but much in the same of "stolen valor" in today's garb I doubt another officer would copy the lancer's style.
A non lancers mameluke with velvet
https://bid.antonycribb.com/m/lot-de...F29%3Fpage%3D9
As for leather I actually don't see many with leather, the vast majority are completely metal sheaths. The lancers generally seem to have velvet, but I still think the fittings point to likely a lancer's sword.
On the auction description Anthony Cribb points to a sword in Dellar pg 109 figure 12.2 as a similar sword. This one also has leather, an early make 1807-10 for an officer of the 22nd light dragoons. It is also entirely possible this is a pre 1822 regulation sword, hence the differences.