I kept on going as you'd expect and I believe I have eventually found him on the 1901 Census in the period where he was missing. There is a Henry Bird, stable lad, aged 22, born at Ashurst, Kent lodging with the village bootmaker at Alfriston, Sussex along with 3 other stable lads. It appears that the village employment revolved around Wingrove Racing stables (until it closed in 1920) and there are so many equestrian folks around to service the stables and race course. Thanks to all.