Dear Peter
I think you are probably correct in your two identifications (the Andrena is usually still known in this country by its older name of A. scotica), but the definitive identification of most solitary bees requires microscopical examination of characters, and these two species are no exception - it is necessary to see features not visible in your photos to confirm their identity. You are welcome to send an example of each to me at Peter Harvey, 32 Lodge Lane, Grays, Essex RM16 2YP.