With such a bare description it is impossible to tell you what you have.
It may be a S&W 1st model, triple lock issued to Canada Model 1907 I believe or it may be one of the later British model 1914 modes which were identical other than missing ejector rod covers. Canada purchased the 2nd model as well. Often they are just referred to as 1st/2nd/3rd/4th model hand ejectors depending on cartridge and lock arrangements.
S&W revolvers cover a huge range and were often copied identically and included similar markings. Usually by Belgian and Spanish makers but over the last 50 years, mostly in Brazil who markets them under the Taurus moniker.
Anyway if you have one of the double action, tip out crane/cylinder, early hand ejector large frame .455 chambered S&Ws it will have been made after 1897 and not considered to be or subject to antique status regulations.
If it is in decent shape it could be quite valuable and desirable to WWI/WWII collectors.