Ok,this maybe a waste of electrons and time, but I see these plastic buttplates on ebay advertised
as Remington Sharps Creedmore buttplates

plastic buttplate

Then I spotted this steel buttplate that looks identical

steel buttplate

So, I wondered, is this second buttplate some sort of rare original, if so, and you need it go ahead and grab it. I'd just like to know more
about the history of these.