Revisited some shots from this winter with a Franka Rolfix. The lens is coated, but the contrast just isn't there. But, I love how the big negative (6x9) lets me crop to my heart's content.
Keep trying different films. I used to shoot both coated and uncoated German folders and found that each lens seemed to respond to different films better in terms of contrast. With a Radionar, try Ilford Pan F for BW and for color, try something by Fuji.... maybe PE could explain this, but that was just my experience.
The contrast in this shot looks good, to my eye. If you want more zip in the primary colours, why not rate the film a wee bit slower and see how that grabs you.