Thanks guys.
I'm going to make silicone moulds from the parts you see in the pictures, to have a resin kit, black color. The external barrel is an aluminum pipe and the goal is to have (more or less) as many movable parts as the original MG34 weapon, always taking care to the final strenght of the whole thing.
In the pictures you cannot see it but the front (barrel) and the stock are removable for easy transport. The bipod is removable too exactly like the real one. It's empty inside so one could fit electronics and so on.
By now I have 4 orders from my Italica Garrison's buddies.
I would like to produce a 3D printed kit but it takes too much time and will cost too much. It's a shame because the weight of this baby is virtually none, the resin kit will weight a bit more.