those are exactly the same as AKS-74 trunnions. not that you would find these readily either. but AKS-74 trunnion in turn is 99% identical to regular AK-74 trunnion. Find yourself an AK-74 bulgy kit and you are all set for your AKS-74U build. you can drill latch pin hole and make it into AKS/U trunnion in like 5 minutes time.