I am looking, anywhere in the world, for the 25x37mm full-frame negative carrier for the Leitz V35 Focomat enlarger.

Leica part #17012

This is not the standard supplied negative carrier that comes with the
enlarger, rather it is the one that is slightly bigger than the 35mm
neg frame (allowing for printing of the natural black border around
the image).

Does anyone have any idea where I could obtain one? OR, does anyone have any advice on making some modification to the standard neg carrier to make it full-frame??

Many thanks, Paul