I have now got the Arducam B0196 web cam lens spacer working in a manual Openflexure Microscope and giving nice images.
[prepared fish blood smear - much larger than mammalian blood cells]
As it is a USB camera this is just using the normal Windows Camera app. There is some green cast to the colour in the centre because we cannot apply a lens shading correction to account for the lens being positioned in a different position from the original design.