The item has arrived without any damage. The GM tube was packed separetly with more layer of package material and hard paper tube. The assembly and operating in insructions on the GitHub are clear. There was two minor problem with assembly: 1. The 100 nF capacitors has 35 nF capacitance in real. They was changed from my stock. 2. The GM tube is shorter than the distance of the holders, so it halfly fixed. It works, but not fully stable mechanically.
all ok thank you