I've now dissected a couple of Syncopacma species I caught in my garden earlier this month, and to my surprise these turned out to be different species: S cinctella on 8th July and S larseniella on 12th July (both males). You can see the subtly different shape of the white cross band in the photos below.
Syncopacma cinctella 08.7.13
Syncopacma larseniella 12.7.13
According to my MapMate there is just one previous VC41 record of each of these species, both made by W.E. Cox (S cinctella at Taff's Well in 1938 and S larseniella in Cardiff in 1939). Strange that both should turn up in my garden in the space of four days.