Trying to figure out the best way to attach this little bugger…what are you guys using??
No more nails glue. It’s a pretty sheltered piece when you think about it, its unlikely that its ever going to be knocked or banged so to bolt it in place, just seems overkill. I’d just recommend a good strong glue
Overkill is goooooood. Small lag bolt from the back in a wood or resin PPD, drilled and tapped hole in a metal PPD. 
See, my concern w/ a lag bolt is that you can only screw up once or twice before you strip out the pilot hole, then you’re screwed..
…I guess that’s probably more my problem than other people’s, lol.
What size lag bolt are you using?
Yeah, the problem with wood or resin parts is that, whichever you’re using bolts or glue, they’re not really removable. 
1/4" lag bolt, 1" long. Don’t forget to use a washer.
What about that 2 part epoxy putty? Think that would cut it, if I drilled a few anchoring holes in the PPD?
I used Marine Goop. Most of the metal details on mine are glued on with it.
Only a propane torch can get it out
To install mine I drilled a hole into my PPD, and I installed a brass insert. Then from inside the pack I used an allen bolt with a washer to hold in it place. It a sturdy bond and if you had to, you could easily remove the PPD and reinstall it with little to no effort. Again this is probably overkill but my goal for this pack was to install everything via brass inserts so if I ever needed to change something I could just remove whatever part I needed and then replace it.
I may be opening up my pack later today to re-install a new amp, so if I do I’ll take some pics.
I just glued mine in place with 2 part epoxy glue!