Does anyone know what 8.5 kw electric shower unit Dophin used with their name on it?

when i worked for them it was New Team who supplied their showers. Hope that helps.

Can you remove the front of the unit? Generally companies such bas dolphin will have another manufacturers product 'rebranded' with their own logo on the front. Inside the parts will be exactly the same as any other unit produced by this manufacturer and a quick 'google' will tell you the manufacturer from the product code inside the unit. Failing that take a photo of the unit and then search the internet for shower manufacturers and find one thats similar to yours and generally it will probably the same one!