Welcome!
First to say - never use Brasso on any coin - it would destroy any value there might be. Anything that won't come off with warm soapy water and a soft sponge is best left, and if the coin is in great condition with good lustre, don't even try that.
Sadly 1967 pennies are extremely common. The range of prices you are seeing is down to Ebayers chancing it in the hope of catching a mug. Even in Brilliant Uncirculated condition you would be lucky to get £1 for one, and anything less they are scrap metal.
@Sword has replied while I was typing with much the same response.