A picture of the back of the object is often as helpful as the front. Also... you say it's silver... so there should be a mark of a maker and mark that it's silver on the object if in fact it is silver... having a pic of that as well would be helpfull.
To me, it does not look silver... if it were Sterling Silver... it would be much more tarnished and having a set of 4... and all being sterling silver, not likely.
It all looks like peweter... and not from the 1880's... at least the frame is not for sure 1880's.
Re: antique silver greek revival roman plaques circa 1880
A picture of the back of the object is often as helpful as the front. Also... you say it's silver... so there should be a mark of a maker and mark that it's silver on the object if in fact it is silver... having a pic of that as well would be helpfull.
To me, it does not look silver... if it were Sterling Silver... it would be much more tarnished and having a set of 4... and all being sterling silver, not likely.
It all looks like peweter... and not from the 1880's... at least the frame is not for sure 1880's.
Best of luck