Are there any marking on the head, it looks similar to a Fatip.
I checked achims website and couldnt find this head in the tech section so going with what i know so far id say its a frankenrazor.
It is a mismatch or Frankenrazor, but it is a great combination.
Very often the Old Type handles split or otherwise failed, and the Fat Handle that came with some Tech razors was a perfect replacement to use the Old Type open comb parts with!
Well, knock me over.
The base plate appears thicker than a standard old type, <sigh> I'm still learning.
They did get thicker after the New Improved came out and the Old Type was demoted to the cheap seats. Here's a side-by-side comparison that Achim put together a while back: