See if you can find, borrow or purchase a Yugo M70 stamped rear receiver stub to use as a guide. Only need one side as you can flop it for opposite or do a drill through etc.
Working an undrilled receiver and virgin trunnion is a larger challange.
I do not recall seeing a Yugo template as it is not the same as Polish etc.
The angle of the teceiver adjustment is an easy fix and can be done after trunnion mock up or install on a belt sander or file or mini air die grinder etc.