armor mod schematics and mod schematics drop off of random trash mobs in EV and KP normal mode.
actually had one drop for me the other day when we decided to goof off with an alt raid in EV.
link to keen mod 24:
Thanks a bunch, I'll toss that into my guide. I haven't seen any drop, but we normally only run nightmare modes if we're doing KP or EV, which isn't that often. Might be worth my while to do some story mode runs now.
Incidentally, I've updated my guide for 1.3. If you see any errors or non-updated info, please let me know!