The Linhof 42mm clamp-on shade and filter holder works. I also use a generic 39.5mm rubber folding hood as well, and it closes with the lens inside my Tech V. There is not much room for movements with this lens in general.
Mine is cammed, and it closes with the camera, so it's a handy lens to walk around with. The camera even closes with the rubber hood and a filter in place. The rubber hood I have is just a generic hood from B&H.