I moulded some out of
'Sugru'; it's like a soft, malleable silicone which sets firm after a few hours.
Sugru It also sticks to most things (a bit like glue);not cheap but very useful for a number of 'odd' repairs around the car/house.It comes in small, foil packs and has a 'shelf-life';I keep mine in the 'fridge to extend the storage time.
The young lady who invented and markets it came up with the idea whilst at University .It's nice to see a start up company doing well.....

James