My Dear Monsieur Ruffian -
Whilst we know that paper cartridges designed to be torn open for muskets were around since the late 1500's,
Combustible Cartridges are a different matter.
I found a reference on wikipedia to A patent filed for a self-contained paper cartridge for a breech loader in 1808, but haave not found the patent.
Sharps slant breech breechloaders (patent 1848) were available as early as 1851, and utilized combustible cartridges, but
the earliest reference I can find offhand for Colt's Combustible Cartridges claims (without any sited sources) they were first offered
" in 1855 for both rifle and pistol firearms" .
hope this helps and
Happy Holidays
prof marvel