1891 argentine mauser bayonet variations,....why?

Can anybody explain why there are 3 variations to the 1891 argentine mauser bayonets? Why start with the nice brass handled, then go to an aluminum, and I've seen wooden ones also. I'm not sure when they made each, whom they were for exactely. :icon_scratch: I'm new to collecting, so I undoubtedly will end up buying them all, but I like to know the story as well.

I have heard the brass was for the Navy---never have confirmed that. I imagine the switch to alum. was due to expense of material, hard to find walnut, last longer or any other practical reason. Never read any authoritive info on this. But I doubt it was for any particular service, except the brass-navy connection makes sense.