PRECISION Anastigmat 18cm F5.5 mystery...?

[koh303]

Just got this lens with a box of junk and dust. Could not find any online info relevant to this.
It is marked:
PRECISION Anastigmat 18cm F5.5 made in Germany, and is mounted in a Betax #3.

Any ideas?
https://scontent-lga.xx.fbcdn.net/hphotos-xpa1/t31.0-8/s960x960/11174344_1581512832126111_1552054346733697688_o.jpg

[desertrat]

Since none of our knowledgeable lens collectors/users have replied yet, I could try a wild guess.

Some of the Goerz dialytes like the Celor had maximum apertures around f5.5. This lens could be a similar design if not made by Goerz.

Doing a reflection count might shed some light. I believe a single dialyte cell should give 4 bright reflections and no dim ones (no cemented surfaces, two air spaced elements).