I just finished adhering the grills to my N26MGR-G tweeters. It wasn't that hard to get them set into place, but I did not feel that they were secure enough to not use a form of adhesive for a better hold. So, on Mark's recommendation, he sent some PVA glue to affix it better. It dries clear, and did the job well.
Here is the grill link from our gracious hosts:
http://meniscusaudio.com/tranducer-n26g ... -1528.html
I ended up placing a drop at the 3 fastener/grill junctions, and wiping away the excess before it dried, and the hold is sufficient. Now I don't have to worry about my daughter (or her friends) 'dinking' these in the future, not that she's come even remotely close to touching the drivers in general.
I like the look!