thanks for that guys and I think I have a solution.

Cable Restraint Vertical - V3
designed to specifically suit 2 wires up to 2.2mm in dia, but can be used for up to 4 smaller wires

Cable Restraint Sloped - V4
designed to specifically suit 2-4 wires up to 1-1.2mm in dia, may pinch the wires up to 2.2mm in dia.

Note: the reason for the slope is that it will be less likely for any wires to rattle out and the gap is 0.3mm smaller in width so better suited for those thinner wires, and the contained area for the wires is exactly the same.

Let me know your thoughts on looks.

I will print some of each in dark grey and white tonight and post here.