We never used to be able to buy it here in Devon either. I loved the stuff when we lived in Lancashire and drank it all the time and then we moved down here I missed it so much along with:
Sarsparilla Tablets
Cough Candy (the proper stuff - not the orange twisty things)
Lancashire cheese (the stuff in the shops down here just isn't the same)
vimto squash
We can buy some of the things down here now but only in a few shops. I don't know of any other shop other than Sainsburys that sells dandelion and burdock. The latest thing that I have had trouble finding down here but get easily up there is Mushroom and Wine Pasta and Sauce although I did find some in Safeways the other day but that might just be because they have been taken over by Morrisons now.
VIMTO I love VIMTO now I CAN get that if I drive 20 miles to the British Sweet Shop in Victoria a long way to go for some pop int it? but worth it cuz I buy some Lion Midget Gems or Wine Gums and a bar of Cadburys Turkish Delight much better than that 'perfumed' Frys Stuff. God, you're making me wanna go
Vimto is good with vodka too, but the diet stuff is evil!
Tell you what I miss is Tab Clear. My ex used to bring it over for me before it was sold in the UK and I was sooooo happy when it was released here. Then it went! Sigh...