There is no such thing as "defacto" legal tender. By definition only legal tender must be accepted as a form of payment - you can choose to accept something else but you don't have to.
Literally every bank in the UK will accept Scottish bank notes - if that's not a defacto legal tender, I don't know what is.
https://en.wikipedia.org/wiki/Banknotes_of_the_pound_sterlin...
But in the real world, they are absolutely defacto legal tender - as above, every bank in the UK (and even many beyond) accepts them.
However, the old Swedish notes had not lost their value because they could still be redeemed.
In a formal legal tender situation, you could to some extent require a private party (within the relevant jurisdiction) to accept the notes in payment of a pre-existing debt. You could contrast this with "having value", "being redeemable", "being in circulation", and "being widely accepted", maybe.