That rear window seems to be everywhere in the US.
People have given them away for $20. Probably not the case in Sweden. But if you can find a decent shipping option for it, its plentiful here. Its good to have a spare.
Ive had one laying around in storage sheds and outside for years and I don't even own a Barracuda. I couldn't even give it away. Its not fragile, I guess the curve makes them stronger.
Good luck with the build, nice car!
Joe