Thanks guys, I've had a look at the Front Rank ones.
They are....
chunky... aren't they?
If there's no alternatives I may be able to make the carbines work, but they may look a tad oversized compared to the Perry and Hicks figures I am planning on using them on.
It surprises me a bit that given that Napoleonics are one of the default wargames ranges, nobody really seems to do a good range of spare weapons.