Hi George,
I too am blown away by your architectural work. In passing, the connection to the Metropolitan did briefly exist. It was an extension of platform one, the line right against the western wall. Amazingly the small signal box on the Met platform that once controlled that junction (located on the eastbound LT platform) survived certainly through the 50s, and I think even into the 60s. The two long platforms in the original form of L. Street - I think that was Nos 9 and 10 - both had an extension far underneath the Great Eastern hotel to unload coal for the central heating and to take away laundry to a central laundry location far far away. When electrification came, that chain or two was cut back, the buffers re-located, and the entire hotel jacked up a foot or two for electrification clearances, at least that is what we were told the raising was for. Previously passengers had to use a very grotty passageway across the heads of those two lines and there was also a link passage to the Met in that area. I seem to recall that there was a storage line between 9 and 10 as well, but I'm not sure.