A second Semioscopis steinkellneriana turned up, and there were four more Elachistids on the floor of the MV trap. I managed a slight improvement in the image quality of two of them:
I'm under no illusion that the photos will be sufficient to identify them, but can anyone suggest what the most likely species is? There are fourteen species in our Carms. list, the most frequent being E.argentella, and although the name might seem appropriate for a moth with a grey, metallic sheen, I believe that this species is significantly larger than the ones I'm catching.