The spacers prints arrived… Quality is okay, not sure how well they will stand up to a bit of bashing during installation and test use. They were eventually made from PC-ABS (PolyCarbonate – Acrylonitrile Butadiene Styrene), Specification: Layer thickness: 150 µm; Filling: 80 %. Apparently this is good for high mechanical stress. Good for fit & form, jigs and fixtures, and enclosures. have to see how things work out.