Khmer style protective seven-headed Naga

Little bronze Khmer style protective naga I found recently. 5" high minus pole or stand. I'm pretty sure it is bronze that has been over cleaned!! It is hollow and remains cold to the touch when held. Would anyone have a clue how old it may be. It is broken at the base end, and has been cleaned for years (polish residue), that apart Ive no clue about age and would very much appreciate any help or pointers ... I have tried hard .... but I've not got anywhere