The Peco LK-83 signal box was ok to build, it did have a problem when cutting the components from some of the sprue`s ( make sure your knife is sharp ), the base tried to warp too when I left it to set, I used Humbrol liquid poly, it was easily rectified using a little more poly and applying weighing for a short while to set firm. Another area that is tricky was adding the ladders and roof again slight warping was rectified.
The peco kit has been said to be based on a signal box in the Potters Bar area.
I have seen a signal box that is much smaller but similar in design that controls the level crossing at Cutsyke in Castleford