Hi Tiso,
I have a distinct feeling tha Zvezda Il-4 is only Maquette kit with rescribed panel lines and little cleaned up. I have Maquette DB-3 and Zvezda Il-4 kits and are almost identical.
I had read about this. Unfortunately the DB-3 is both rare and poor. Probably the Il-4 of Zvezda could be roughly adapted to DB-3 with few pieces.
They preserved the scomposition of the wings that was thought to replace the engines (I suppose) for the DB-3, but didn't make this version.
I wonder if they thought to make a late Il-4 with arrow wings and kept the outer consoles of the wings separed for this reason.
Regards
Massimo