Hey. From Russia with love (for real). I'm in process of restoration of 1990 JCESE. Engine's been rebuilt by previous owner approx. 10 yeats ago, it has new housings with black labels, new rotors, caps (may be shaft too). Mileage after rebuilt ~3000 km. Car kept in siberian semi-warm garage for 9 last years and gone faded in all meanings, but engine still starts (but working bad and stops in a minute).
Vac system was messed up completely, so i found schemes and colorized them. I have some questions that I'm going to ask in other threads or here. Anyway, I welcome everyone.

I uploaded schemes on Imgur: Mazda Eunos Cosmo 20B-REW vacuum scheme https://imgur.com/gallery/XPBIVRt

 



 

Nicely done, but I did this in 2012 on Project OldTree. Your diagram certainly looks nicer than my MSPaint effort back then though. One thing I would suggest if you've not already done so is to join the Cosmo Owners Group on Facebook. I'm one of the earlier members, with a considerable amount of what's known being based on what was discovered on Project OldTree.