"Has anyone else found the maximum aperature of f45 an issue with these lenses for general pictorial photography?"
The 14" is in an Ilex #5 shutter. When you send it out for a CLA, it rather easy for the tech to lengthen the slot for the aperture arm travel. The iris can be closed down to 3mm before binding. That would be less than f/90 and into the diffraction limit for the lens.