I need help. Bergmann MP18.

[Amadeus]

Hello. Sorry for my english, not enough practice to use. I am from Belarus, Dictator's country. In our country, it is forbidden for an ordinary citizen to have a firearm, it is very difficult to obtain a permit. Therefore, it is impossible to acquire rare weapons. But many men are fond of collecting models of weapons, making replicas of wood and metal. I am also fond of the weaponry theme and decided to make a replica of the legendary MP18 / 1 metal, but unfortunately, I cannot find any drawings or dimensions of the main parts anywhere. Using a photo from the Internet, I was able to draw sketches with approximate dimensions. A big request to the owners of MP18 / 1, if it's not difficult, help clarify the dimensions of the receiver. Thanks in advance.