I have the Turissa Ultramatic [made in Switz.] that I learned to sew on when I was young. I believe it was made first in 1953. Mine wore out some rubber gaskets and up until then, it was running fine. After being in storage for so long, I took it out and have oiled it hoping to see some progress. My problem is I can't find anywhere to get an old service manual. I wonder if I should try to sell it for parts? I have the cams that go with it.
You are right, you drop the bobbin in the case [which opens by pushing a button and it drops down. You then lay the bobbin case in and shut it. I've never seen another machine other than pictures but it was an excellent machine, heavy-duty and could take on any job. For some reason, I thought it was made by Elna? All I can find is the Turissa name.