1997 fiat ducato brake part problem

Hi everyone
Can any one help me I am trying I get a replacement part for my camper a 1997 fiat ducato 2.5jtd cat with a Fenth body .i have gone to the main dealer to source a valve that is set to to apply brake pressure to the wheels evenly it is like a load sensing valve but has not got the arm on it to adjust the valve depending on the load. Fiat came up with two types both of which are wrong.any one know who might help me on this problem .

Thanks for that I will try them they are not to far from me.i made contact with east coast campers in Wicklow who may have a second hand part off a 1998 Peugeot boxer camper he is parting out.