I know pronunciation is a fraught topic - and involved the beating of a dead horse - but I am always interested in documentary evidence of pronunciation. In London, I had carefully listened to the way ngain was pronounced by the older members, back in the 1990s and this was from time to time a topic of discussion around the Shabbat table of the former Shamash, Mr Valier - we were aware of a slight difference in the pronunciation of the ngain in initial and final position....in initial it had more of a g , as in 'gn' feel to it, and final, more of a nasal as in the word 'sing' , as in 'ng' It was never a guttural in London, as it is sometimes elsewhere.The issue at Bevis Marks is largely academic, as the historic pronunciation is no longer used....occasionally it briefly surfaces when an elder gentleman makes the beracha upon an ngaliyah. I have found the first documentary evidence for what I heard with my own ears.....a Christian called Thomas Keyworth,who in 1817 in Spitalfields published a 'Principia Hebraica' - and I strongly suspect his somewhat lengthy description of the pronunciation on ngain was based on his own observations at Bevis Marks.