questions about stock calipers..

im lookin at the possibility of putting a set of calipers like those on my 87 vw gti. i dont have any specs on the calipers but im trying to figure out if they can be put on.what years & what models are calipers like those from?
those(in the pic) are on the ml55 & they go on a 13.6 rotor. im probably going to upgrade to a 12.3 rotor from the audi tt & use a set of 16" bbs rs rims that came off a benz.
i dont know if this will work but im researching to see if it can.
any help is greatly appreciated!thank you


