[TPIN] Plating (historically)

[Achias1 at mchsi.com]

I have a pre 1890's DeJaques cornet in raw brass which I considered silverplating at one time but have 
since decided (with help from Steve Hubbard) to leave as is.

My questions: 

How common were raw brass instruments during the heyday of cornet playing? 

Was it an economic issue, or aesthetic, or aural?

Were they kept polished or allowed to go "au natural?"

Anyone?

Dave