Hi SELfour50, it's not a big ask, but merely a question of having enough time to get it done by Saturday. Again, to summarize, the fronts are ventilated and slotted, the rears are solid and slotted. I could have the rear Brembos slotted for you......
As far as rear ventilated discs are concerned, you will only find those on the 1969 300SEL 6.3's. They're obviously VERY RARE, but I might be able to cobble up a couple of SERVICED second hand units - a lot would depend on the condition of units I might be able to procure.
You will also need to keep in mind that you would not be able to use the standard rear calipers, and that is a cost factor that you would need to allow for. Back in the late '60's and very early '70's Mercedes applied some strange methods in making calipers fit specific disc rotors. Obviously, in some applications, the rotors were too wide for the calipers so they simply spaced them out and used longer bolts to hold the two caliper halves together. Might be able to illustrate this in due course.
Anyway, I am digressing. You will need to give me a phone call today if we are to have any chance at all to get things organized for you. 0428-50-1800 Regards Styria