choiliefan, you win the most-awake price !
that filter tray, if I am not mistaken, is the rare black wrinkle paint filter holder Leitz USA made for the early round head Focomat Ic !!
Beagleagle, that filter holder means you do not need the filter tray in the head. This holder replaces the red filter, but with a different, longer shoulder screw. If that is present you're in total luck !!
The lens, if a Focotar, looks like either one of the two later versions . . . but difficult to see. Anyway, that would make sense as this grey Ic generally came with one of those.