This Cornish beer talk, persuaded me to look out my CAMRA guide to ale in Cornwall 1984, from what I recalled Cornwall was a bit of an ale desert, when used to go down there a fair bit back then.
Basically you had St Austell brewery, which was OK, and fuck all else, except the mighty must visitness of The Blue Anchor in Helston.
The Blue Anchor, and I've no idea if it's still there, had its own brewery on site, and did the legendary Spingo Extra Special....which was falling in ditch stuff.
Back then only one or two pubs boasted a guest beer....notably The Cobweb in Boscastle, which was an interesting place which carried 6X, a long way from home.
When I lived down in Cornwall, working in Plymouth about 6 years ago, Spingo beers were still going. The Fortesque on Mutley Plain used to have a Spingo night.
Mutley Plain is begging for a pub called the Dastardly.