It sure looks like copper to me. Hand made, in the hammmered style, that is they left the texture of the hammer instead to smoothing out the Body. I did notice the old and hand made looking rivots that hold the Handles to the base. I would say that it looks antique too me, My guess is pre 1850's but that is just a guess. Without any maker marks finding age and history is a very daunting task. I would also suspect the hole in the bottom was added at a later date, shouldn't affect value too much is so. As for cleaning I would do very little if any, based on the fact that it shows the age and could devalue the item a bit, yes it would look shiny, but better is based on personal opinion. Most collectors would rather have it looking old much like it does now. As for value without maker marks or history, date and etc. I would say you are looking at 50 to 75 dollars in value. And would be sought after most my interior decorators. Nice Vase you have there.
