No MG34...absolutely wrong hole pattern plus the IG88 rifles vented barrel jacket is metal, no resin or fiberglass.The barrel on that is from the MG34 , they took a MG34 Barrel shroud and slipped it over the MP44 barrel. Find a replica MG34 and use the barrel shroud, thats what I was thinking.
But it also looks like the barrel shroud on the Sterling SMG. They used resin shrouds on the E-11 so this could be two of those on this rifle.
When I was poking around Etsy, I found this.
looking for these, are you?