Anybody ever seen an Unbranded IWC cal 88?

Hello,

I stumbled upon this piece a while ago: An IWC cal 88 12lig. INCA from around
1947.
But completely unbraded on the bridge side except the cal 88 marking under
the balance and the serial number at its usual place between the bridges.
It bares the Probus Scafusia insignia under the dial though.

The dial itself seems to be a Stern Freres one with the star
and the seperate digits of their customer code for IWC (61).

I would be grateful for any thoughts on which other company could have IWC
made this for
as I've never seen an unbranded cal 88 before, only older pocket movements of
theirs...
Thanks !

Hi Josef,

i have seen it on movements that where delivered to watch making schools. But
those did come with alternative decorations. In earlier times IWC also
delivered movement to other watch manufacturers, like Huber in Munich or the
ZenTra organization.

br

Cromagnonman

Thank you very much, Cromagnonman !

What marvels me that the dial seems to be unbranded as well.
I don't see any sign of a worn off insignia or any indication of a re-dial...