Are you sure it has a long bobbin? A long bobbin doesn't exactly have a bobbin case, rather, it has a shuttle. Most machines that came with that configuration were really old sewing machines (treadles, mostly).
This is what a long bobbin looks like:
[ATTACH=CONFIG]616003[/ATTACH]
I did a couple of searches and didn't find any photos of Turissa sewing machines old enough to have a long bobbin and shuttle system. Here's some information:
https://www.fiddlebase.com/swiss-machines/turissa/
Here's a bobbin case for sale that says it's for a Turissa. I don't know if they all have the same bobbin case, as I've never seen a Turissa machine.
https://www.ebay.com/itm/Sewing-mach...sAAMXQupJRFx2T
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