You should have a good look at this. May help your task.
https://forum.accurateshooter.com/threads/model-70-center-screw-pillar-mod.4096065/#post-38672227
Type: Posts; User: Grey Kiwi
You should have a good look at this. May help your task.
https://forum.accurateshooter.com/threads/model-70-center-screw-pillar-mod.4096065/#post-38672227