Looking for a Deckel SO spare part drawing

Hi,
I've bought a Deckel SO in bad condition, now it's near finished but it is one part I cannot find as spare part or find any drawing, it's the part which is made to block the rotation of the head on 90°.
Does somebody had the dimensions or a single picture to make a new one, I have only found this plan but it's a so complicated part which had certainly some specifications for the right use.
Thanks a lot if you can help me, and have a good week-end in any manner. ;-)
The part is number 21, 22 and 23 on the drawing.
https://zupimages.net/up/20/07/0r12.jpg

https://zupimages.net/up/20/07/0v0a.jpg

https://zupimages.net/up/20/07/6sxk.jpg

It's seems that nobody has this original part, impossible to buy from Deckel, my last solution is to search on forums specialized in tool grinding???