On 14 Jan, 04:35, wrote:
There was an exit at the extreme rear end of the EB Central Line
plaform. You went up stairs then turned right into a corridor which
lead due north to reach the lifts lower landing. At top level these
lifts allowed access directly onto the concourse of Broad Street BR
station. All this was still there disused until the Broadgate Centre
was built in the mid-1980s.

Do you happen to know where the spiral staircase was, and what
happened to it?