I just fitted the pre-1997 doorcatches to my 1990 4/4 4-seater. I think they call it the Mk 2 catches, designed for the Morgans without the scuttle bar. It was quite simple to fit and it works very effective.
Ruut Bianchi Morgan PlusFour 2023 Bentley Midnight Emerald Morgan 4/4 4-seater 1990 Royal Ivory