Joint Coinage for Mainz, Nassau-Saarbrucken, Frankfurt and Hesse-Darmstadt 1623-37

From 1623-37, a joint coinage was issued for Mainz, Nassau-Saarbrucken, Frankfurt and Hesse-Darmstadt, and the coinage shows the coats of arms of each of the four on the obverse.

I know that Krause lists this under Mainz (with a separate subheading), but shouldn't this be a separate issuer for the Numista catalog?

These are listed without any mention of the joint coinage status at:
https://en.numista.com/catalogue/pieces74612.html

Mainz also issued jointly with Hesse-Darmstadt 1623-39:
https://en.numista.com/catalogue/pieces134890.html

Thanks I wil see how we can implement these under separate issuers.

Here are photos of a coin of the 4-location joint coinage (1636 BS):

http://www.elfreeman2.com/t18/ma636r.jpg

http://www.elfreeman2.com/t18/ma636o.jpg

You have my permission to use the photos for the Numista catalog, if you wish. Please attribute them to elfreeman (my eBay username).