Who declared GB to be a thing?
Scotland existed in some form before the Westphalia Treaty was even thought of.
And here's the map as the Treaty of Westphalia drew it:
Scotland and Ireland seperate from England.
Why would Scotland be fucked (if they had the rights to oil and gas revenues from the North Sea)?
And I say this as someone who is fairly ambivalent to Scottish independence and who holds next to no sympathy with the SNP.