My Mum has held shares in Carnival for 30 years. She has a certificate for shares worth a lot of money. Over the years she moved address and lost touch with the company. She must have accumulated many dividends but where are they? Who will hold them & how does she find out how much they are worth?
I think the first step is to contact Carnival Investor Relations. They can give you information about what attempts they have made to pay dividends since the address has changed. There may be some hoops that you have to jump through to get the funds, but the simple answer is to call them and find out.