Actually, it's uncommon for German folding cameras to have light seals. In fact, almost never.

With a $350 budget, you have a lot of options. You can get anything from a nice Rolleiflex or Rolleicord to a folding camera with a built-in rangefinder.

You probably could pick up a Zeiss Ikon Mess Ikonta 524/16 (6x6) with a Tessar. Or possibly an Agfa Isolette III with a Solinar. Make sure that both have been serviced.

I'm not up on the Japanese medium format cameras, so I won't offer any thoughts on those.