Ratio 500 GWR Signal Box Kit 00 HORatio OO HO GWR Signal Box Although modelled on the signal box at Highley, Severn Valley Railway, this box was designed by the private signalling firm Mackenzie and Holland, making it suitable for many areas of the country. The Ratio Signal Box Interior kit 553 will provide a wealth of interior detail. Supplied with pre coloured parts although painting and or weathering can add realism; glue is required to complete this model. Footprint 92mm x 51mm