having looked again at the Least Yellow Underwing photo's I've thought of something that presumably is really obvious but only I could answer...
When trying to chivvy the moth to a safer place before just picking it up it's wings were open and I don't remember seeing any really obvious markings like the LYU has...
It
may have helped if I'd mentioned this when LYU was first suggested!
of course this could be an old faded exaple with very faded "underwings" but
