Ole,
It isn't mysterious; I just wanted to know if there was some reason to "invest" in it over say, the 300mm f/4.5 Heliar I already have in shutter. You can tell I'm a sucker for old pretty glass just because of this post (like I need another "non-standard" shutterless barrel lens)!
Nope, won't screw into a #5 Compound, the cells are too small diameter; haven't tried and Ilex #5 - I just assumed it wouldn't fit which may be a bad assumption. The only Ilex #5 I have is a Kodak branded shutter which I understand has different threads from the Ilex Universal. But I had the same thought, German lens too big for a #4 - it should drop into a Compound #5.
Norm, a test run will be made, but the glass has enough fogging to reduce contrast a bit. No spanner notches, so if I want to disassemble and clean the glass, its O-ring time.
Thanks everyone!
Steve