Ulceby box has already been demolished, apparently. It's curious that Garden Street has survived all this time since the 1993 resignalling of the area.
According to one of the signallers who was working Roxton Siding box, every single piece of equipment will be going into storage, to be used as spares for the remaining signal boxes. Seems like a sensible decision rather than chucking it all in a skip!
As far as I am aware Garden Street cannot be demolished as it is a listed building/preservation order on it but like so many old buildings in Grimsby it will just slowly rot away until it becomes dangerous the will have to be demolished.