Hello,
Sorry to interrupt your thread but I also got my Lancasters this week and I was also curious how could I check the cones. Finally I realised that the back panel can be unscrewed so I took off the back. As I can see the cones are in mint condition but since there is a green paint on the screws holding the speakers in their place, I don't want to unscrew them.
I also have 15" Golds in it. I've read somewhere that during a period Tannoy's production quality was not the very best (reference: http://www.troelsgravesen.dk/tannoyMG15.htm) so I would like to ask what should I check in order to find out if my Golds are OK or not. Also this link mentions the crossover part values might not be correct (due to age).
They sound very nice, but I would like to make sure that my Lancaster sound at their best.
Thanks for your help!