I dont know if you are still looking for this item.
The agents in the UK used to be Dantec Dynamics in Bristol. Since they lost the contract for Medtronic Urology most of the guys have left there, including the Cal engineer. If you mail them through the website they might be able to help, (i.e. one in a cupboard somewhere), Otherwise I dont think you will find one, as DNI was bought by Lion Heart (Ultramedic) then Fluke, who dropped all the old systems.
(I dont work there now either, so I cannot help directly)