TM mp5 receiver help

[Burmaluke]

Hi everyone,
I've been busy restoring one of my mates old tm mp5a4's and I want to swap the lower receiver as it's pretty horrendous in its current state.
What I'm wondering is whether a metal cyma lower will work with the tm upper and gearbox. Or alternatively will an ics mp5 navy style receiver fit with the tm upper.
Thanks for any help guys, and if someone happens to have a spare tm mp5 lower receiver I'll happily buy it.