The third pistol is a breech cartridge loading example with hammers.

No such example is listed anywhere on the Pedersoli website. Only the muzzle loaders have hammers.

Anyone know more about these cartridge howdahs with hammers? Were they shotgun (.410) or rifled (.45 LC)?

This example:

https://www.athlonoutdoors.com/article/pedersoli-howdah/

Pedersoli Howdah Specs

Caliber: .45 Colt/.410
Barrels: 10.25 inches
Overall Length: 17 inches
Weight: 4.5 pounds (empty)
Sights: Brass bead front, folding leaf rear
Stock: Walnut
Action: Sidelock, exposed hammers
Finish: Browned barrels, color-case hardened steel furniture
Capacity: 2
MSRP: $2,035