FM Rail 'purple' Class 31/6 No. 31601 was named Gauge 'O' Guild in a ceremony at FM Rails headquarters in Derby on 7 September. The naming was to celebrate the 50th birthday of the Gauge 'O' Guild which brings together a large number of people interested in modelling this gauge. The unveiling of the cast plate was performed by Mrs Lyn Evans, wife of Gauge 'O' Guild Chairman John Evans.

Celebrity '31' No. 31601 was previously named The Mayor of Casterbridge.

To mark the naming, No. 31601 has also been re-branded with large FM Rail logos.