Re: Fag packet maths
There are so many taxes, fees, and such that aren't counted toward the Scots contribution. I mean, take things like oil company licenses. That most likely goes to the north sea account rather than the Scottish account, and therefore don't show up in the book-keeping as having been contributed by Scottish assets.
Where is VAT counted for the Tesco and ASDA shops? In England or Scotland? What about BBC license fees? What about all the other little charges and fees and taxes. Fag packet tax? Beer and wine tax?
The only thing one can know for sure is what comes down the pipe from Westminster after the Barnett formula has been applied. And, you have to give it to the SNP, after the dreadful mess Labour made of the Scottish parliament (the building!) and with their tribal belief that Scottish voters always belonged to them and nobody else, the SNP has done a pretty good job of balancing the books up there.
Sure, like any political party they're going to inflate their own positives and hide away their own negatives. But there's a reason why SNP got a majority in a system designed to avoid majorities.