Does the real millitary Yugo reciever come with X, and Y dimples?, and do normal RPK recievers have X, and Y dimples?....
No, RPK & Yugo RPK type receivers do NOT have the X & Y stampings. This is because they are 1.5mm thick instead of the 1.0mm AKM thickness.
Why do correct 1.0mm AK receivers need the X & Y stamping, I'll quote someone else here:
The original AK-47 milled receiver has a wall thickness of 1.6/1.5mm.
When they settled on 1mm thick metal for the AKM, they wanted to keep parts interchangable to the greatest extent possible. This required several details to make the old parts compatible with the thinner profile of the new receiver.
The X & Y stampings were one of these details. The axis pins were made to fit correctly through a 1.6/1.5mm wall. The space between the large end and the groove for the retaining wire (in this case the autosear spring, in semi's one for the various wire springs used by different factories) assumed a 1.6/1.5mm wall. With a 1mm wall, the pin could move inward, and would stick out the other side. The X & Y stampings did stiffen the receiver, but this was not their purpose. The purpose is to make the effective wall thickness 1.6/1.5mm when measured from the outside of the receiver to the inside of the deformed metal in the X & Y stampings.
Now the RPK / Yugo RPK type receivers used 1.5mm thick steel, so the X & Y stampings were not needed.