Solitary Wasp / Potter Wasp / Mason Wasp

Not one I've seen before

Possibly Ancistrocerus oviventris

Feeding on White Melilot (Melitotus alba)

Location: Upper beach. sandy and shelly. 
Vegetation mostly grasses, clover, vetches, trefoils, rest harrow, yarrow, centaury, meadow cranesbill, strawberry, etc.

Size: Slightly smaller than a common wasp (Vespula vulgaris).


I am struggling for a definitive ID on the species of this individual.

I have looked at examples of Ectemnius (but their heads are broader than the thorax.  Also didn't find one with the broad black abdominal band.)

I have looked at examples of Symmorphus. No matches for anything that was likely to be seen in Scotland.

I have looked at examples of Ancistrocerus

Best fit was Ancistrocerus oviventris (aka Ancistrocerus pictus) but the legs of my example are redder than the yellow abdominal bands.