Low patent use numbers lead me to agree with Terry.
In the 19th century British system, low patent numbers have no relationship to year of filing. They started each year with patent #1 and worked up from there. So #10,000-1870 is older than #399-1890. You need to know the year as well as the number to make sense of those marks.
I can not find either of these patent numbers. I searched all 7 volumes of "Patents for Inventions of Small Arms" and all 3 volumes of Nigel Brown. Hopefully some one else can find them.
Pete