15 minutes of research Gebby? Only 15 minutes? Naw, that's not nearly enough.
Here, this may help to get you started:
Forgotten Realms Adventures (AD&D 2E hardback)
pages 11-13 has rules for guns and cannon
page 20 has more fireams references in the Gond section
If you have Wizards and Rogues of the Realms, look up the Lantan section. You'll find some notes on the Lantanese use of arquebuses.
Just look up Lantan in every FR product you've got that includes details on that nation, in fact. I'd focus on the AD&D 2E boxed set and the 3E FRCS.
FRCS has something interesting.. Look over the free starting gear table in the FRCS. Humans from the Nelanther Isles and the sword Coast may begin play with a pistol and powderhorn. Same thing for natives of Lantan. Same thing for gnomes from the Western Heartlands. Pistols, hell yeah!
Read up on Gond. Faiths and Avatars AD&D 2E is a good source. There are others.
Next, branch out by reading up on Kara Tur. Fireworks. :)
It's undeniable; canon FR does include guns, fireworks, etc. If you don't like that, change it. As the DM, you are in charge of these things.
