I have the virtually identical 521/16. It has a Novar instead of the Tessar and I believe you have a flash sync that is missing on the 521. I carry it around almost daily, folded up in my pocket.

The hood to fit your specs might not exist. You would either have to find one to fit the Series ring (probably a #6), or a Series adapter for a screw-on filter. Anything made out of rubber to fit a series ring probably rotted away long ago, and who knows if such an adapter has ever been made. Either way it would be pretty tight to fit inside when folded up - these things are marvelously engineered for compactness. I have seen metal lens shades for Series, so they do exist. If you want to use any filters,you'll just have to get used to carrying them separately.

What is you fastest shutter speed? Mine is 1/250 and I have found a happy spot with Tmax-400 and an orange or red filter. You may get more contrast with the Tessar and not find any filtering necessary.

Have fun with it, man. It's the most fun camera I own.