I received my Componon in great nick...

However despite it having 37mm thread like the one that does fit, the threads on the Componon are recessed back from the surface and can't grip the female enlarger threads.

Even if I push it in place, a 2nd problem pops up... The Componon inner element protrudes through the enlarger and stops the shutter working as it is where the shutter is.

So I figured I need a shallow 37mm extension type tube. I only need about 5-6mm for the extension tube to screw in then the Componon can screw into it.

I am looking on the internet to see if there is anything out there that can make this work without having to go to a custom machine shop (and this isn't feasible anyway just to get this enlarger going).