Hello pennypup ...
You pose a great question ...
I've had both pleasant and unpleasant results when cleaning silver/silverplate items .
On the one hand , it makes it possible to honestly describe defects in a piece offered for sale .
On the other hand , defects will often be accentuated or further damage can be caused by the 'cleaning/polishing' process .
Original patina can be an issue , I've found , in some buyers of antique sterling silver .
In my case , I like to ask myself - "Would I want to display/use heavily tarnished silver in my house ?"
It can be a tough call to make , esp. with silverplate .