Non-rhotic accent, eh? Estuary English?

"ˈθʌrə"'s was interesting to me, I'd render "thorough" in my ideolect (Southern-inflected General American) "θʌrow". Is your pronunciation "standard" in British English (or whatever the prestige variant where you're from is)?

Also, I think you meant "ðə ˈmɛtᵊl Pb lɛd"