The fine and well-presented box seen here is Gleldon Sidings which has also been known as Glendon East signal box. It was located just a short distance from the point where the Corby route diverged from the MML. The tracks stretching of into the distance lead to Corby and thence onwards to Manton Junction via the famous Harringworth viaduct. As well as controlling the junction it also controlled access to some exchange sidings to the right of this view where Stewarts and Lloyds (towards the end of mining operations that is) mined iron stone. Whilst the box has long gone the line is in somewhat of a renaissance having now been re-doubled after BR singled it and is now electrified seeing a regular service to and from St.Pancras. The following photograph shows the scene in more recent years, see.....
https://www.ontheupfast.com/p/21936chg/25598648204/x222010-10-41-corby-londonst-pancras