Until recently I owned a 1954 Cessna: the only maintenance program I could find was a 100 hour inspection as detailed in the POH ( the 100 hour inspection to be carried out at 100 hours or annually). So, would it be necessary to do a 50 hour/6 month check (as now) and could EASA/CAA make changes to the maintenance schedule in contradiction to the manufacturers (design authority) instructions?