Punktal was a brand name of Ernst August Siepen who was a razor manufacturer in Solingen, Germany. (They also branded some razors as "Rapido")

They initially they manufactured straight razors and then started selling DE's.
It's not clear whether they actually manufactured their DE's as the same heads are available on other brands such as Emir. However it stands to reason that they were manufactured in a single factory, sold to different manufacturers as OEM razors. That manufacturer then matched the heads with their own branded handles.
At some point they also sold Electric Razors.

To the best of my knowledge they only made the following two differential razors.

Punktal Open Comb/Solid Bar	Punktal Slant