The Midland pre-built their boxes in knocked down form at Derby and installed them on-site. St. Albans South box is a type 2A box was opened in 1892 closing as a signal box in December 1979 but soldiering on for two months as the home for the station announcer! It was a grade two listed structure so was not demolished but got into a dreadful state of dereliction. This was until a trust was formed in 2003 and a lease agreement was set up Network Rail. After a complete renovation, it opened to the public in October 2008. I have yet to pay a visit but it is on my list of things to do in the near future during one of their open days, see.....
http://www.tlr.ltd.uk/sigbox/home.eb