Apparently I have an Atco H5 24" petrol lawnmower which recently failed because of a worn double sprocket in the drive chain. I believe it is an H5 because I saw an identical mower that has been restored. From the documentation in that topic it shows a user manual and the item I need is H 254 which is a double gear (10 and 26 teeth). Recent enquiries to various companies has turned up nothing, the model number doesn't seem to be relevant. I assume that is because it is a vintage mower. Can anyone direct me to someone who can help source the gear please. I have included a front and back picture. Thanks in advance.