Hi there and thank you for your question,
To buy a gun you'll need to a gun licence. As part of your application for a gun licence the police will do an investigation, and they'll find the fact that you have this "mental record", or whatever you call it.
If the police are happy that you should have a gun licence notwithstanding this mental record, then you'll be able to buy the replica gun. If they are not happy, then you won't get a licence, and you won't legally be allowed to buy the gun.
If you're saying that the gun is a replica and that it does not actually work (i.e. it doesn't fire anything) then it would technically not be a gun and you could buy it.
Hope that makes sense?
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