The FG42 is not on the list of "enumerated weapons" in the MA AWB, so the AG's "guidance" from July 2016 doesn't apply.
So, does it meet the "feature test"? If it has two or more of these things, it's an AW:
(i) a folding or telescoping stock;
(ii) a pistol grip that protrudes conspicuously beneath the action of the weapon ;
(iii) a bayonet mount;
(iv) a flash suppressor or threaded barrel designed to accommodate a flash suppressor; and
(v) a grenade launcher;
It's got a pistol grip, so that's your one allowed feature. It doesn't seem to have a folding stock, bayonet lug, or a grenade launcher. The muzzle device, if it's marketed as a "flash hider", will need to be replaced. Whatever device is on there will then need to be pinned to the barrel, and hey presto, you have a non-Assault Weapons FG42.
EDIT: CORRECTION: It appears that it might have a bayonet lug. If it does that would need to be removed/disabled as well.