But the "Europe project" originally was about free trade. It worked pretty well for the most part, too: we managed with multilateral free trade agreements for years without things like legislative policy and currency getting centralised as well, and there are still alternative platforms for cooperation like the EFTA and EEA, which for example include some Scandinavian nations that are not part of the EU.

Given the UK's disproportionate strength, I don't see why it couldn't move to a similar relationship to what those Scandinavian nations have with Europe, being outside of the main EU and the Eurozone but still sharing common ground elsewhere. So until someone wiser about economics tells me otherwise, I think I stand by my previous position: whatever the pros and cons of being in the EU more generally, financially it's almost certainly in the UK's interest to leave.