Well i manged to fix the arms and i used a better way than using screws directly into the shoulders ^^
So here are my broken arms
A closer look yoy can see where the little plastic parts broke
I took 2 of these ikea screws, and cut the base in half.
They already exist in smaller sizes, called spacers or stand off i think.
i didnt have the patience to wait so i cut those ikea screws
I dremelled the soulders so the custom spacers i cut would fit
I tested, and reworked the holes in the shoulders, sanded the custom spacers so i could get a perfect fit
Once i was happy, i glued the custom spacers in the shoulders holes with Loctite Super Glue, screwed the arms to the body and... VOILA!
It's way much better than that flimsy plastic and now when i tighten the screw its really helps the arms stay up if i want, without damaging the shoulders.
I will probably use another type of screw to attach the arms to the body, those i have are a little bit thinner that those who came originally with the ikea screw and add a rubber seal in side the chest shoulder joint to avoid any damages when i tight the screws.
Amazing work.
One advice if your arms are not damaged, DO NOT tighten the screws.
The original screws will damage the tiny plastic parts.
And yeah, that´s a truth