Who does Austin/Morris 1100/1300. Hydro-lastic Displacer Hose replacement or kit?

Is there a company that will repair Hydro-lastic Displacer Hoses or can one use the Mini Displacer hose replacement? Or has anyone any ideas on how to replace just the hose, when the displacer its self is fine. Also where is the cheapest UK place to by fluid in bulk? (25ltrs+) Thanks