Possible Caspian Gull & Glaucous Gull

A 1st Winter Glaucous Gull showed well near our local tip over the weekend along with a 2nd winter Iceland Gull which unfortunately didn't stay put long enough to photograph.  Then amongst a large gathering of gulls in a nearby field was a possible Caspian Gull.  The bird was an adult which showed many of the features of a Caspian Gull and was seen along side Herring Gulls for comparison.  The first two images are the possible Caspian - any comments welcome.