That appears to be a Durst Sixtif lenspanel for a M600 enlarger. I do not know of any other Durst enlarger that uses a 70mm lens panel. The later 60x series used the larger 77mm lens panel.
Used with a 28 or 35mm lens.
Many of my Durst lens panels do not have any printing on it. I do not know why some do and some do not.
BTW, great drawing.