Thanks. It appears to be based on a Salmson 2A2

BAPC.452 “N5177” – Sopwith 1½ Strutter Replica – Private location, Merstham, Surrey – ex “B9708” one-time Macclesfield Historic Aviation Society

http://www.airliners.net/photo/UK-Air-Force/Sopwith-1-Strutter-Replica/1038067