Figured I would just answer your PM in this thread.
The one bolt I have that is out of the adjuster is 25mm long and is a 6mm metric with a 1.0mm pitch. I assume the other bolts would be identical but can't know for sure.
https://www.dropbox.com/s/5p8ckispfwy59ig/DSC_0127.JPG
https://www.dropbox.com/s/iatjpvey2m1lemg/DSC_0128.JPG
https://www.dropbox.com/s/3s75ygjypkfzs5t/DSC_0130.JPG
https://www.dropbox.com/s/us7w9h0y67eqwsg/DSC_0131.JPG
I was told the bolts are magnesium by the shop that did the repairs and that the bolts alone can not be replaced. I looked at my units and see no physical reason the bolts could not be as it looks like simply a threaded hole to me. The bolt is very light, best scale I had only goes as low as grams but it was only 2 grams.
https://www.dropbox.com/s/91tqgcevxv8wjcu/DSC_0136.JPG
https://www.dropbox.com/s/6u5j3wazdln0xht/DSC_0144.JPG
I'm in Canada and the parts + labor to do this job at an indy shop was around $2k including diagnosis, oil flush/change. Dealer estimated $4,800 and with goodwill they may cover 2/3 of the bill but I had DP's on so there was likely no hope for goodwill really. I did not drop the pan to find the bolt heads because I knew I wasn't keeping the car.
This pic is all I had of the unit still attached to the cam, probably not much help.
https://www.dropbox.com/s/9cdnhbqpo1bjo11/DSC_0002.JPG
Few pics of the unit itself with the cover that these bolts hold on taken off as well.
https://www.dropbox.com/s/dhxuqegoc2zu1mh/DSC_0132.JPG
https://www.dropbox.com/s/3ngosjkerbnnytm/DSC_0133.JPG
https://www.dropbox.com/s/9t1n87shlht6iuy/DSC_0138.JPG
Couldn't get pics to upload to the forums so I linked to my dropbox, no idea how long the links will stay active so if someone wants to download and repost the pics feel free.
Hope this helps, good luck with your N55's...