Have I got a Manta 19 ?

I have just been given a trailer sailor and it is very similar to the Manta 19 that i am now viewing but i cant be certain. The layout of the boat is the same and the shape of the windows. Could any body let me know where to look for more clues to my boats origination ie. where to find serial number / make etc. Its a lovely boat and my first. I cant wait to get out on the water. many thanks. chris.<