There are reports of engineer and mine clearance teams in US flak jackets with M1, but I'm yet to see a photo showing them in use. Almost all footage and imagery has ANZAC troops in greens with bush hats.
If you were to do an infantry pack in M1 and flak, it would be likely purely hypothetical and be of limited use outside of 'what-if' gamers. A couple of sculpts in a dedicated engineer pack would be feasible, but I'd still prefer a pack in greens with bush hats before any troops with helmets or vests.