Glow Worm Compact 80e Domestic Hot Water Switch?

Does anyone know if you can get a retaining clip and seal for the DHW switch on a Glwo worm compact 80e by themselves - our boiler is leaking at the switch and before I take the switch out to see what the O ring is like I'd like a spare. The clip has corroded so will probably snap - everythingelse with the boiler is fine

Part numbers appreciated

Thanks

Martin