DIALUX-POL (circa 1970) trinocular head replacement part help

[moutinho]

Hello all,

I have a Trinocular Leitz Dialux-Pol I believe is from 1970 series. I am looking for a trinocular head replacement.
I have been trying for years finding on ebay. No luck 
Does anyone know where I could get this part?

Best Regards
Andre