What company or companies are the shares in?
Some company shareholder registrars are able to "dematerialise" such paper cert shares to convert them to electronic holdings.
Some also offer share dealing services for small shareholders.
I have a bunch of Vodafone shares (similarly the original shares plus a load accumulated through reinvested dividends) and I recently contacted their registrars (Equinity) who explained to me how I can get these converted to a nominee account shareholding and how I can sell them through Equinity too.