![Cool 8)](./images/smilies/icon_cool.gif)
It also occurs to me that the same principle could be used to make reversed lens or microscope objective adapter for these lenses. For that I would increase the thickness of the clips and add more rigidity to the front plane ... and naturally leave a hole for gluing a step-down/up adapter. The former would be used with microscope objective and the latter reversed for reversed lenses. I will likely make one for my lens just for fun, but any other lens needs someone to take the measurements ... and the suitability of the adapter would depend on the accuracy of the measurements.
The price for the lens cap was 45€ + shipping from Shapeways. The adapters would likely cost roughly the same ... for this size. Larger ones would be more expensive. I'm afraid the shape doesn't really fit extrusion printing at home.
Any interest or comments?