On the subject of gum rubber brake hoods.Natural ozone in the atmosphere attacks natural rubber and turns it into dust.Used to service Draeger breathing sets, face masks had high natural rubber content any brittle cracks turned to splits with dire results for wearer.Answer to problem. Regular application of soft paraffin wax BP. Rub it well in with fingers.Masks last indefinitely.Should work on gum rubber.Soft paraffin wax BP available from chemists shops drug stores etc.Worth a try.
SEASONS GREETINGS ALL. John English .North Yorkshire England. Riding mid 80s "woodrup" original 105 groupset.