Well I still think it's a Small Blue
Here are a couple of shots from the
Gallery to try and illustrate the points I made earlier. First one of your Small Blue shots, note the pale rings to the spots and the fairly small dots on the forewing underside.
And here's a Holly Blue from Jon which lacks obvious pale rings to the spots and shows the dashes on the underside of the forewing.
Also Holly Blues tend to have a fairly uniform metallic bluey silver underside, whereas in Small Blues there is more of a contrast between the metallic blue at the base of the wings and the greyish colour on the rest of the underside, although this feature can depend a lot on the condition of the butterfly!
Guy