Sorry, on the fluid, you would ask for the atf for the 722.6 transmission, and all current production atf is the same, so:
Is all current production MB ATF the same; or should I specify the fluid by transmission type (722.630)?
YES and YES.
MB, as far as I know, doesn't even market ATF for the non-electronic transmissions, except for this special ATF they sold on gallon jugs to fix a particular shifting complaint on an older tranny
(what was described as a double-engagement).
I believe the quote onebadviper gave is a little low, I think the fluid is closer to $14/liter from the dealer.