[petrochemist]

Originally Posted by Alex1994

Not sure it is a bellows attachment, that looks more like a very old monorail view camera to me. It has a shutter on the front (bit marked Synchro-Compur with various speeds indicated). The bit at the back looks like an eyepiece, not a place to attach a camera.

Dallmeyer is a very old British camera brand, probably the make of the lens.

This http://www.earlyphotography.co.uk/site/entry_C567.html looks a lot like yours.

The version in the photos doesn't have the full range of movements, so I think it must be the F version. Unfortunately I don't think that will be as valuable.