Campagnolo rear mech identification

[MartinB123]

Can't say I've seen one like this before! If it helps to identify then I've enclosed a pic of the calipers that came with it.

 

[ferrus]

mech’ is a Croce d’Aune
https://www.disraeligears.co.uk/site/campagnolo_croce_daune_b010-sm_derailleur.html