Exactly how many Stiffy and Mo scripts Roberts wrote, or indeed when he was first engaged to write material for them, has not yet been established. It is also unclear as to how much he contributed to the scripts, whether this comprised an entire scenario, including dialogue (except for improvised sections), or just some of the jokes. The first established association between the Roberts and Phillips was as co-directors of the Fullers' 1925 Christmas pantomime, Robinson Crusoe.