Olympic aquatics: Advice wanted on verifying a coin please.

[NK77 1]

Hi I have got into collecting coins in circulation over the past year. I went to an auction last week with my dad as he collect stamps and there were some coins. I won an Olympic carded set with a completor medal which I was delighted with. When I got home I was looked through and noticed the aquatic has lines over the face! (I'm glad i found oit after!) I'm trying to verify if this is real and welcome advice please. I have been told it's the low numbered carded ones which it appears to be. Am I best contacting the mint or does anyone have one and can show me the number and or a photo? The photos when I google differ greatly. Many thanks in advance. 

[declan03 149]

Hi.

Here is a picture of a real one. Hope it helps.