It is, in fact, just that.....a PEERLESS 28ga single shot shotgun.....
Made by Remington, branded as PEERLESS.
One would have to have the stamps from the barrel [small letters, symbols, etc.]
to determine date, but most importantly, what steel it is.
Most likely the barrel is damascus, fires black powder shells, so DO NOT use modern
smokeless shells in it. [until it is determined what steel]
It could well have been produced between 1893 and 1915.