If you can prove to me that this appalling piece of tat was made by Holland & Holland, then I will eat my keyboard, in public, with a sauce of your choice.
It is not known when Harris Holland started his own manufacturing, but it is estimated to be in the 1850s - by that time the British military had long parted ways with the flintlock musket, and were at the beginning of adopting the Pattern 53 rifled musket made in Royal small Arms Factory at Enfield Lock in North London.
Furthermore, if you can find any proof that they made a flintlock musket for the common soldier, the promise I made on line 1 will equally apply.