Have you forgotten the IMF ballout, the Winter of Discontent and later Maggie going begging for a rebate because Britain was the "sick man of Europe"? We were shagged before we joined the EEC, and I hope leaving it's successor doesn't take us back to those dark days.
Talking of this recent event bringing back manufacturing jobs is bullshit that some politicians -- especially on the left -- like to peddle, but in fact if manufacturing comes back it will more likely be automated. Anyway, this depreciation doesnt allow us to compete with China's labour costs, or any of its competitors now that it is getting too expensive. When the pound dropped after the 2008 financial crises, the relative side of our trade gap didn't shrink... it's not price that's preventing people buying our products.
If half the international banking industry leaves then we'll end up with a gap in governement finances that will cause them to make cuts more painful than anything George Osbourne did in the last six years, I can guarantee that a boom in exports won't cover this difference. And as the economy contracts the size of the interest payments on the goverment's debts will become the fifth biggest expense... finance industry wins again.