It is indeed a percussion version of a cartridge revolver. There are places in this world (United Kingdom) where possession of a cartridge handgun is illegal, but a percussion (or flintlock, etc.) handgun is allowed under special circumstances. Initially Uberti, and then more recently Pietta, produced a version of their popular Cattleman (an 1873 Colt closed frame Peacemaker replica) that uses percussion caps instead of cartridges for sale in that market. The gun does indeed have a completely useless ejector mechanism because the 1873 Colt has one, and it does not have a loading lever because the 1873 Colt didn't have one. It is necessary to remove the cylinder and use a cylinder loading stand or tool to load the chambers with powder and ball.
The gun makes no sense as a historical article because it never existed before Uberti produced it, and the need to remove the cylinder to load it makes it difficult to use. However, it did allow UK residents to shoot the venerable 1873 Colt design, and on that score it is a success. It's an excellent shooting gun and in my opinion a very nice looking gun as well.
Uberti's design utilized the hammer with an offset firing pin and a matching offset hole in the frame, along with a cylinder with offset nipple installations in order to make it difficult, if not impossible, to modify the gun to shoot with a cartridge cylinder. This was necessary to obtain clearance to sell the gun in the UK.