I printed the Mount in PTEG and do not have any problems with strength. I have increased the Mount base by 1mm. Hopefully that will be sufficient for PLA. You can re-download the Mount file and print a new part.
As for the Grommet, I apparently created this on the fly and so not have the design file any longer. The Grommet is for aesthetics only and you can install the filter without the Grommet. If you would like to create your own, the object is very simple as it is only a tube with a flange. Tinkercad.com is a free and easy tool that you can use for that purpose. All that being said, I looked at the Grommet I printed and the flange is more than a mm thick. That should be sufficient and you should not have any issues separating it from the print bed. I would check your printer settings, in particular the settings for the 1st layer.
I hope this helps.