To fit the signs all that is required are two 1.5mm drill holes 30mm apart for each leg and a little glue. There are three variations available.
Tiny Signs BR Station Signs Scottish Region 4mm Scale
DT574 Woodland Scenics N Scale Mini-Series Service Station Signs
Tiny Signs N22 BR Modern Image Station Signs N Gauge
Tiny Signs N25 Early Station Signs N Gauge
Sankey Scenics BRM4(3) British Rail Station Additional Station Signs (Pk3) 4mm
British Railways Southern Region Model Railway Station Signs Pack N Gauge 2mm