Window winder mechanism

I have an 1925 EPK Coupe, the windows are all seized which I did know about with the sale of this relic.

The trim is now removed to gain access to the window winder mechanisms and I discovered that the gear boxes (window transmission drive assemblies) have totally disintegrated with time.

They are an aluminium housing with 2 small brass gears that turn the drive screw, that raises and lowers the window.

3 rivets attach the units to a mounting plate, that is part of the inner trim.

Can anyone tell me if these are common to several models and which years of production, and/or interchangeable between models?

Is there anyone remanufacturing these or does anyone have non fatigued, good condition units for sale here?

Any info greatly appreciated,

regards Roger