Just wanted to add a couple pics of my MP5 with its new parts installed.
I replaced the plastic front handgrip a metal RIS and vertical front grip. The battery is wired to the back and is covered with a velcro sleeve. I put a couple of internal upgrades that I posted earlier. Oh yeah, a tactical sling as well.
This MP5 only shoots around 320fps and ~900rpm. Great for CQB games. What fun!