Thanks, nameless and Redroger. I certainly heard the added "l" a lot when I lived there. I'm not sure it was just added to proper names, though. I'm sure it was also added to other words, such as "What a good ideal".
Wikipedia has the following:
"A dialect of English is spoken by some Bristol inhabitants, known colloquially as Bristolian, or even more colloquially as "Bristle" or "Brizzle". Bristol natives speak with a rhotic accent, in which the r in words like car is pronounced. The unusual feature of this dialect, unique to Bristol, is the Bristol L (or terminal L), in which an L sound is appended to words that end in an 'a' or 'o'.[159] Thus "area" becomes "areal", etc. "
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