It is a No. 0 made in 1901.
A hardware store catalog from that year



The forend is from another gun made in either 1898 or 1918.

The No. 0 was supplied with Damascus barrels until London Steel was offered in 1907. If the barrels are not marked LONDON or possibly ARMOR just forward of the flats then the barrels are damascus, and have clearly been blued possibly to hide that fact.
If blued by hot caustic salts, the ribs, and potentially the tubes will separate over time.

I'm sorry, but can you return the gun?
Damascus barrels can be used with appropriate loads, but will require an evaluation by a qualified barrel specialist regarding wall thickness, pitting and the top and bottom ribs.