Unusual Divider or Compass

[UScollector]

Hello, I collect among other things antique drafting or drawing instruments from the 17th to 19th century. I just picked up these from French Ebay, the square section is different than anything I have seen in museums, collections or books. They are 19 cm long and much heavier than most dividers, I think they might be early to mid 18th century German. They do not have the same feel as the dozens of English and French examples I have.

So has anyone seen or have a reference to anything like them?

Thank you,